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/*

  OpenLayers.js -- OpenLayers Map Viewer Library

  Copyright (c) 2006-2013 by OpenLayers Contributors
  Published under the 2-clause BSD license.
  See http://openlayers.org/dev/license.txt for the full text of the license, and http://openlayers.org/dev/authors.txt for full list of contributors.

  Includes compressed code under the following licenses:

  (For uncompressed versions of the code used, please see the
  OpenLayers Github repository: <https://github.com/openlayers/openlayers>)

*/

/**
 * Contains XMLHttpRequest.js <http://code.google.com/p/xmlhttprequest/>
 * Copyright 2007 Sergey Ilinsky (http://www.ilinsky.com)
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * http://www.apache.org/licenses/LICENSE-2.0
 */

/**
 * OpenLayers.Util.pagePosition is based on Yahoo's getXY method, which is
 * Copyright (c) 2006, Yahoo! Inc.
 * All rights reserved.
 * 
 * Redistribution and use of this software in source and binary forms, with or
 * without modification, are permitted provided that the following conditions
 * are met:
 * 
 * * Redistributions of source code must retain the above copyright notice,
 *   this list of conditions and the following disclaimer.
 * 
 * * Redistributions in binary form must reproduce the above copyright notice,
 *   this list of conditions and the following disclaimer in the documentation
 *   and/or other materials provided with the distribution.
 * 
 * * Neither the name of Yahoo! Inc. nor the names of its contributors may be
 *   used to endorse or promote products derived from this software without
 *   specific prior written permission of Yahoo! Inc.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 
 * POSSIBILITY OF SUCH DAMAGE.
 */
/* ======================================================================
    OpenLayers/SingleFile.js
   ====================================================================== */

/* Copyright (c) 2006-2013 by OpenLayers Contributors (see authors.txt for
 * full list of contributors). Published under the 2-clause BSD license.
 * See license.txt in the OpenLayers distribution or repository for the
 * full text of the license. */

var OpenLayers = {
    /**
     * Constant: VERSION_NUMBER
     */
    VERSION_NUMBER: "Release 2.13.1",

    /**
     * Constant: singleFile
     * TODO: remove this in 3.0 when we stop supporting build profiles that
     * include OpenLayers.js
     */
    singleFile: true,

    /**
     * Method: _getScriptLocation
     * Return the path to this script. This is also implemented in
     * OpenLayers.js
     *
     * Returns:
     * {String} Path to this script
     */
    _getScriptLocation: (function() {
        var r = new RegExp("(^|(.*?\\/))(OpenLayers[^\\/]*?\\.js)(\\?|$)"),
            s = document.getElementsByTagName('script'),
            src, m, l = "";
        for(var i=0, len=s.length; i<len; i++) {
            src = s[i].getAttribute('src');
            if(src) {
                m = src.match(r);
                if(m) {
                    l = m[1];
                    break;
                }
            }
        }
        return (function() { return l; });
    })(),
    
    /**
     * Property: ImgPath
     * {String} Set this to the path where control images are stored, a path  
     * given here must end with a slash. If set to '' (which is the default) 
     * OpenLayers will use its script location + "img/".
     * 
     * You will need to set this property when you have a singlefile build of 
     * OpenLayers that either is not named "OpenLayers.js" or if you move
     * the file in a way such that the image directory cannot be derived from 
     * the script location.
     * 
     * If your custom OpenLayers build is named "my-custom-ol.js" and the images
     * of OpenLayers are in a folder "/resources/external/images/ol" a correct
     * way of including OpenLayers in your HTML would be:
     * 
     * (code)
     *   <script src="/path/to/my-custom-ol.js" type="text/javascript"></script>
     *   <script type="text/javascript">
     *      // tell OpenLayers where the control images are
     *      // remember the trailing slash
     *      OpenLayers.ImgPath = "/resources/external/images/ol/";
     *   </script>
     * (end code)
     * 
     * Please remember that when your OpenLayers script is not named 
     * "OpenLayers.js" you will have to make sure that the default theme is 
     * loaded into the page by including an appropriate <link>-tag, 
     * e.g.:
     * 
     * (code)
     *   <link rel="stylesheet" href="/path/to/default/style.css"  type="text/css">
     * (end code)
     */
    ImgPath : ''
};
/* ======================================================================
    OpenLayers/BaseTypes/Class.js
   ====================================================================== */

/* Copyright (c) 2006-2013 by OpenLayers Contributors (see authors.txt for
 * full list of contributors). Published under the 2-clause BSD license.
 * See license.txt in the OpenLayers distribution or repository for the
 * full text of the license. */

/**
 * @requires OpenLayers/SingleFile.js
 */

/**
 * Constructor: OpenLayers.Class
 * Base class used to construct all other classes. Includes support for 
 *     multiple inheritance. 
 *     
 * This constructor is new in OpenLayers 2.5.  At OpenLayers 3.0, the old 
 *     syntax for creating classes and dealing with inheritance 
 *     will be removed.
 * 
 * To create a new OpenLayers-style class, use the following syntax:
 * (code)
 *     var MyClass = OpenLayers.Class(prototype);
 * (end)
 *
 * To create a new OpenLayers-style class with multiple inheritance, use the
 *     following syntax:
 * (code)
 *     var MyClass = OpenLayers.Class(Class1, Class2, prototype);
 * (end)
 * 
 * Note that instanceof reflection will only reveal Class1 as superclass.
 *
 */
OpenLayers.Class = function() {
    var len = arguments.length;
    var P = arguments[0];
    var F = arguments[len-1];

    var C = typeof F.initialize == "function" ?
        F.initialize :
        function(){ P.prototype.initialize.apply(this, arguments); };

    if (len > 1) {
        var newArgs = [C, P].concat(
                Array.prototype.slice.call(arguments).slice(1, len-1), F);
        OpenLayers.inherit.apply(null, newArgs);
    } else {
        C.prototype = F;
    }
    return C;
};

/**
 * Function: OpenLayers.inherit
 *
 * Parameters:
 * C - {Object} the class that inherits
 * P - {Object} the superclass to inherit from
 *
 * In addition to the mandatory C and P parameters, an arbitrary number of
 * objects can be passed, which will extend C.
 */
OpenLayers.inherit = function(C, P) {
   var F = function() {};
   F.prototype = P.prototype;
   C.prototype = new F;
   var i, l, o;
   for(i=2, l=arguments.length; i<l; i++) {
       o = arguments[i];
       if(typeof o === "function") {
           o = o.prototype;
       }
       OpenLayers.Util.extend(C.prototype, o);
   }
};

/**
 * APIFunction: extend
 * Copy all properties of a source object to a destination object.  Modifies
 *     the passed in destination object.  Any properties on the source object
 *     that are set to undefined will not be (re)set on the destination object.
 *
 * Parameters:
 * destination - {Object} The object that will be modified
 * source - {Object} The object with properties to be set on the destination
 *
 * Returns:
 * {Object} The destination object.
 */
OpenLayers.Util = OpenLayers.Util || {};
OpenLayers.Util.extend = function(destination, source) {
    destination = destination || {};
    if (source) {
        for (var property in source) {
            var value = source[property];
            if (value !== undefined) {
                destination[property] = value;
            }
        }

        /**
         * IE doesn't include the toString property when iterating over an object's
         * properties with the for(property in object) syntax.  Explicitly check if
         * the source has its own toString property.
         */

        /*
         * FF/Windows < 2.0.0.13 reports "Illegal operation on WrappedNative
         * prototype object" when calling hawOwnProperty if the source object
         * is an instance of window.Event.
         */

        var sourceIsEvt = typeof window.Event == "function"
                          && source instanceof window.Event;

        if (!sourceIsEvt
           && source.hasOwnProperty && source.hasOwnProperty("toString")) {
            destination.toString = source.toString;
        }
    }
    return destination;
};
/* ======================================================================
    OpenLayers/BaseTypes.js
   ====================================================================== */

/* Copyright (c) 2006-2013 by OpenLayers Contributors (see authors.txt for
 * full list of contributors). Published under the 2-clause BSD license.
 * See license.txt in the OpenLayers distribution or repository for the
 * full text of the license. */

/**
 * @requires OpenLayers/SingleFile.js
 */

/** 
 * Header: OpenLayers Base Types
 * OpenLayers custom string, number and function functions are described here.
 */

/**
 * Namespace: OpenLayers.String
 * Contains convenience functions for string manipulation.
 */
OpenLayers.String = {

    /**
     * APIFunction: startsWith
     * Test whether a string starts with another string. 
     * 
     * Parameters:
     * str - {String} The string to test.
     * sub - {String} The substring to look for.
     *  
     * Returns:
     * {Boolean} The first string starts with the second.
     */
    startsWith: function(str, sub) {
        return (str.indexOf(sub) == 0);
    },

    /**
     * APIFunction: contains
     * Test whether a string contains another string.
     * 
     * Parameters:
     * str - {String} The string to test.
     * sub - {String} The substring to look for.
     * 
     * Returns:
     * {Boolean} The first string contains the second.
     */
    contains: function(str, sub) {
        return (str.indexOf(sub) != -1);
    },
    
    /**
     * APIFunction: trim
     * Removes leading and trailing whitespace characters from a string.
     * 
     * Parameters:
     * str - {String} The (potentially) space padded string.  This string is not
     *     modified.
     * 
     * Returns:
     * {String} A trimmed version of the string with all leading and 
     *     trailing spaces removed.
     */
    trim: function(str) {
        return str.replace(/^\s\s*/, '').replace(/\s\s*$/, '');
    },
    
    /**
     * APIFunction: camelize
     * Camel-case a hyphenated string. 
     *     Ex. "chicken-head" becomes "chickenHead", and
     *     "-chicken-head" becomes "ChickenHead".
     *
     * Parameters:
     * str - {String} The string to be camelized.  The original is not modified.
     * 
     * Returns:
     * {String} The string, camelized
     */
    camelize: function(str) {
        var oStringList = str.split('-');
        var camelizedString = oStringList[0];
        for (var i=1, len=oStringList.length; i<len; i++) {
            var s = oStringList[i];
            camelizedString += s.charAt(0).toUpperCase() + s.substring(1);
        }
        return camelizedString;
    },
    
    /**
     * APIFunction: format
     * Given a string with tokens in the form ${token}, return a string
     *     with tokens replaced with properties from the given context
     *     object.  Represent a literal "${" by doubling it, e.g. "${${".
     *
     * Parameters:
     * template - {String} A string with tokens to be replaced.  A template
     *     has the form "literal ${token}" where the token will be replaced
     *     by the value of context["token"].
     * context - {Object} An optional object with properties corresponding
     *     to the tokens in the format string.  If no context is sent, the
     *     window object will be used.
     * args - {Array} Optional arguments to pass to any functions found in
     *     the context.  If a context property is a function, the token
     *     will be replaced by the return from the function called with
     *     these arguments.
     *
     * Returns:
     * {String} A string with tokens replaced from the context object.
     */
    format: function(template, context, args) {
        if(!context) {
            context = window;
        }

        // Example matching: 
        // str   = ${foo.bar}
        // match = foo.bar
        var replacer = function(str, match) {
            var replacement;

            // Loop through all subs. Example: ${a.b.c}
            // 0 -> replacement = context[a];
            // 1 -> replacement = context[a][b];
            // 2 -> replacement = context[a][b][c];
            var subs = match.split(/\.+/);
            for (var i=0; i< subs.length; i++) {
                if (i == 0) {
                    replacement = context;
                }
                if (replacement === undefined) {
                    break;
                }
                replacement = replacement[subs[i]];
            }

            if(typeof replacement == "function") {
                replacement = args ?
                    replacement.apply(null, args) :
                    replacement();
            }

            // If replacement is undefined, return the string 'undefined'.
            // This is a workaround for a bugs in browsers not properly 
            // dealing with non-participating groups in regular expressions:
            // http://blog.stevenlevithan.com/archives/npcg-javascript
            if (typeof replacement == 'undefined') {
                return 'undefined';
            } else {
                return replacement; 
            }
        };

        return template.replace(OpenLayers.String.tokenRegEx, replacer);
    },

    /**
     * Property: tokenRegEx
     * Used to find tokens in a string.
     * Examples: ${a}, ${a.b.c}, ${a-b}, ${5}
     */
    tokenRegEx:  /\$\{([\w.]+?)\}/g,
    
    /**
     * Property: numberRegEx
     * Used to test strings as numbers.
     */
    numberRegEx: /^([+-]?)(?=\d|\.\d)\d*(\.\d*)?([Ee]([+-]?\d+))?$/,
    
    /**
     * APIFunction: isNumeric
     * Determine whether a string contains only a numeric value.
     *
     * Examples:
     * (code)
     * OpenLayers.String.isNumeric("6.02e23") // true
     * OpenLayers.String.isNumeric("12 dozen") // false
     * OpenLayers.String.isNumeric("4") // true
     * OpenLayers.String.isNumeric(" 4 ") // false
     * (end)
     *
     * Returns:
     * {Boolean} String contains only a number.
     */
    isNumeric: function(value) {
        return OpenLayers.String.numberRegEx.test(value);
    },
    
    /**
     * APIFunction: numericIf
     * Converts a string that appears to be a numeric value into a number.
     * 
     * Parameters:
     * value - {String}
     * trimWhitespace - {Boolean}
     *
     * Returns:
     * {Number|String} a Number if the passed value is a number, a String
     *     otherwise. 
     */
    numericIf: function(value, trimWhitespace) {
        var originalValue = value;
        if (trimWhitespace === true && value != null && value.replace) {
            value = value.replace(/^\s*|\s*$/g, "");
        }
        return OpenLayers.String.isNumeric(value) ? parseFloat(value) : originalValue;
    }

};

/**
 * Namespace: OpenLayers.Number
 * Contains convenience functions for manipulating numbers.
 */
OpenLayers.Number = {

    /**
     * Property: decimalSeparator
     * Decimal separator to use when formatting numbers.
     */
    decimalSeparator: ".",
    
    /**
     * Property: thousandsSeparator
     * Thousands separator to use when formatting numbers.
     */
    thousandsSeparator: ",",
    
    /**
     * APIFunction: limitSigDigs
     * Limit the number of significant digits on a float.
     * 
     * Parameters:
     * num - {Float}
     * sig - {Integer}
     * 
     * Returns:
     * {Float} The number, rounded to the specified number of significant
     *     digits.
     */
    limitSigDigs: function(num, sig) {
        var fig = 0;
        if (sig > 0) {
            fig = parseFloat(num.toPrecision(sig));
        }
        return fig;
    },
    
    /**
     * APIFunction: format
     * Formats a number for output.
     * 
     * Parameters:
     * num  - {Float}
     * dec  - {Integer} Number of decimal places to round to.
     *        Defaults to 0. Set to null to leave decimal places unchanged.
     * tsep - {String} Thousands separator.
     *        Default is ",".
     * dsep - {String} Decimal separator.
     *        Default is ".".
     *
     * Returns:
     * {String} A string representing the formatted number.
     */
    format: function(num, dec, tsep, dsep) {
        dec = (typeof dec != "undefined") ? dec : 0; 
        tsep = (typeof tsep != "undefined") ? tsep :
            OpenLayers.Number.thousandsSeparator; 
        dsep = (typeof dsep != "undefined") ? dsep :
            OpenLayers.Number.decimalSeparator;

        if (dec != null) {
            num = parseFloat(num.toFixed(dec));
        }

        var parts = num.toString().split(".");
        if (parts.length == 1 && dec == null) {
            // integer where we do not want to touch the decimals
            dec = 0;
        }
        
        var integer = parts[0];
        if (tsep) {
            var thousands = /(-?[0-9]+)([0-9]{3})/; 
            while(thousands.test(integer)) { 
                integer = integer.replace(thousands, "$1" + tsep + "$2"); 
            }
        }
        
        var str;
        if (dec == 0) {
            str = integer;
        } else {
            var rem = parts.length > 1 ? parts[1] : "0";
            if (dec != null) {
                rem = rem + new Array(dec - rem.length + 1).join("0");
            }
            str = integer + dsep + rem;
        }
        return str;
    },

    /**
     * Method: zeroPad
     * Create a zero padded string optionally with a radix for casting numbers.
     *
     * Parameters:
     * num - {Number} The number to be zero padded.
     * len - {Number} The length of the string to be returned.
     * radix - {Number} An integer between 2 and 36 specifying the base to use
     *     for representing numeric values.
     */
    zeroPad: function(num, len, radix) {
        var str = num.toString(radix || 10);
        while (str.length < len) {
            str = "0" + str;
        }
        return str;
    }    
};

/**
 * Namespace: OpenLayers.Function
 * Contains convenience functions for function manipulation.
 */
OpenLayers.Function = {
    /**
     * APIFunction: bind
     * Bind a function to an object.  Method to easily create closures with
     *     'this' altered.
     * 
     * Parameters:
     * func - {Function} Input function.
     * object - {Object} The object to bind to the input function (as this).
     * 
     * Returns:
     * {Function} A closure with 'this' set to the passed in object.
     */
    bind: function(func, object) {
        // create a reference to all arguments past the second one
        var args = Array.prototype.slice.apply(arguments, [2]);
        return function() {
            // Push on any additional arguments from the actual function call.
            // These will come after those sent to the bind call.
            var newArgs = args.concat(
                Array.prototype.slice.apply(arguments, [0])
            );
            return func.apply(object, newArgs);
        };
    },
    
    /**
     * APIFunction: bindAsEventListener
     * Bind a function to an object, and configure it to receive the event
     *     object as first parameter when called. 
     * 
     * Parameters:
     * func - {Function} Input function to serve as an event listener.
     * object - {Object} A reference to this.
     * 
     * Returns:
     * {Function}
     */
    bindAsEventListener: function(func, object) {
        return function(event) {
            return func.call(object, event || window.event);
        };
    },
    
    /**
     * APIFunction: False
     * A simple function to that just does "return false". We use this to 
     * avoid attaching anonymous functions to DOM event handlers, which 
     * causes "issues" on IE<8.
     * 
     * Usage:
     * document.onclick = OpenLayers.Function.False;
     * 
     * Returns:
     * {Boolean}
     */
    False : function() {
        return false;
    },

    /**
     * APIFunction: True
     * A simple function to that just does "return true". We use this to 
     * avoid attaching anonymous functions to DOM event handlers, which 
     * causes "issues" on IE<8.
     * 
     * Usage:
     * document.onclick = OpenLayers.Function.True;
     * 
     * Returns:
     * {Boolean}
     */
    True : function() {
        return true;
    },
    
    /**
     * APIFunction: Void
     * A reusable function that returns ``undefined``.
     *
     * Returns:
     * {undefined}
     */
    Void: function() {}

};

/**
 * Namespace: OpenLayers.Array
 * Contains convenience functions for array manipulation.
 */
OpenLayers.Array = {

    /**
     * APIMethod: filter
     * Filter an array.  Provides the functionality of the
     *     Array.prototype.filter extension to the ECMA-262 standard.  Where
     *     available, Array.prototype.filter will be used.
     *
     * Based on well known example from http://developer.mozilla.org/en/Core_JavaScript_1.5_Reference/Global_Objects/Array/filter
     *
     * Parameters:
     * array - {Array} The array to be filtered.  This array is not mutated.
     *     Elements added to this array by the callback will not be visited.
     * callback - {Function} A function that is called for each element in
     *     the array.  If this function returns true, the element will be
     *     included in the return.  The function will be called with three
     *     arguments: the element in the array, the index of that element, and
     *     the array itself.  If the optional caller parameter is specified
     *     the callback will be called with this set to caller.
     * caller - {Object} Optional object to be set as this when the callback
     *     is called.
     *
     * Returns:
     * {Array} An array of elements from the passed in array for which the
     *     callback returns true.
     */
    filter: function(array, callback, caller) {
        var selected = [];
        if (Array.prototype.filter) {
            selected = array.filter(callback, caller);
        } else {
            var len = array.length;
            if (typeof callback != "function") {
                throw new TypeError();
            }
            for(var i=0; i<len; i++) {
                if (i in array) {
                    var val = array[i];
                    if (callback.call(caller, val, i, array)) {
                        selected.push(val);
                    }
                }
            }        
        }
        return selected;
    }
    
};
/* ======================================================================
    OpenLayers/BaseTypes/Bounds.js
   ====================================================================== */

/* Copyright (c) 2006-2013 by OpenLayers Contributors (see authors.txt for
 * full list of contributors). Published under the 2-clause BSD license.
 * See license.txt in the OpenLayers distribution or repository for the
 * full text of the license. */

/**
 * @requires OpenLayers/BaseTypes/Class.js
 */

/**
 * Class: OpenLayers.Bounds
 * Instances of this class represent bounding boxes.  Data stored as left,
 * bottom, right, top floats. All values are initialized to null, however,
 * you should make sure you set them before using the bounds for anything.
 * 
 * Possible use case:
 * (code)
 *     bounds = new OpenLayers.Bounds();
 *     bounds.extend(new OpenLayers.LonLat(4,5));
 *     bounds.extend(new OpenLayers.LonLat(5,6));
 *     bounds.toBBOX(); // returns 4,5,5,6
 * (end)
 */
OpenLayers.Bounds = OpenLayers.Class({

    /**
     * Property: left
     * {Number} Minimum horizontal coordinate.
     */
    left: null,

    /**
     * Property: bottom
     * {Number} Minimum vertical coordinate.
     */
    bottom: null,

    /**
     * Property: right
     * {Number} Maximum horizontal coordinate.
     */
    right: null,

    /**
     * Property: top
     * {Number} Maximum vertical coordinate.
     */
    top: null,
    
    /**
     * Property: centerLonLat
     * {<OpenLayers.LonLat>} A cached center location.  This should not be
     *     accessed directly.  Use <getCenterLonLat> instead.
     */
    centerLonLat: null,

    /**
     * Constructor: OpenLayers.Bounds
     * Construct a new bounds object. Coordinates can either be passed as four
     * arguments, or as a single argument.
     *
     * Parameters (four arguments):
     * left - {Number} The left bounds of the box.  Note that for width
     *        calculations, this is assumed to be less than the right value.
     * bottom - {Number} The bottom bounds of the box.  Note that for height
     *          calculations, this is assumed to be less than the top value.
     * right - {Number} The right bounds.
     * top - {Number} The top bounds.
     *
     * Parameters (single argument):
     * bounds - {Array(Number)} [left, bottom, right, top]
     */
    initialize: function(left, bottom, right, top) {
        if (OpenLayers.Util.isArray(left)) {
            top = left[3];
            right = left[2];
            bottom = left[1];
            left = left[0];
        }
        if (left != null) {
            this.left = OpenLayers.Util.toFloat(left);
        }
        if (bottom != null) {
            this.bottom = OpenLayers.Util.toFloat(bottom);
        }
        if (right != null) {
            this.right = OpenLayers.Util.toFloat(right);
        }
        if (top != null) {
            this.top = OpenLayers.Util.toFloat(top);
        }
    },

    /**
     * Method: clone
     * Create a cloned instance of this bounds.
     *
     * Returns:
     * {<OpenLayers.Bounds>} A fresh copy of the bounds
     */
    clone:function() {
        return new OpenLayers.Bounds(this.left, this.bottom, 
                                     this.right, this.top);
    },

    /**
     * Method: equals
     * Test a two bounds for equivalence.
     *
     * Parameters:
     * bounds - {<OpenLayers.Bounds>}
     *
     * Returns:
     * {Boolean} The passed-in bounds object has the same left,
     *           right, top, bottom components as this.  Note that if bounds 
     *           passed in is null, returns false.
     */
    equals:function(bounds) {
        var equals = false;
        if (bounds != null) {
            equals = ((this.left == bounds.left) && 
                      (this.right == bounds.right) &&
                      (this.top == bounds.top) && 
                      (this.bottom == bounds.bottom));
        }
        return equals;
    },

    /** 
     * APIMethod: toString
     * Returns a string representation of the bounds object.
     * 
     * Returns:
     * {String} String representation of bounds object. 
     */
    toString:function() {
        return [this.left, this.bottom, this.right, this.top].join(",");
    },

    /**
     * APIMethod: toArray
     * Returns an array representation of the bounds object.
     *
     * Returns an array of left, bottom, right, top properties, or -- when the
     *     optional parameter is true -- an array of the  bottom, left, top,
     *     right properties.
     *
     * Parameters:
     * reverseAxisOrder - {Boolean} Should we reverse the axis order?
     *
     * Returns:
     * {Array} array of left, bottom, right, top
     */
    toArray: function(reverseAxisOrder) {
        if (reverseAxisOrder === true) {
            return [this.bottom, this.left, this.top, this.right];
        } else {
            return [this.left, this.bottom, this.right, this.top];
        }
    },    

    /** 
     * APIMethod: toBBOX
     * Returns a boundingbox-string representation of the bounds object.
     * 
     * Parameters:
     * decimal - {Integer} How many significant digits in the bbox coords?
     *                     Default is 6
     * reverseAxisOrder - {Boolean} Should we reverse the axis order?
     * 
     * Returns:
     * {String} Simple String representation of bounds object.
     *          (e.g. "5,42,10,45")
     */
    toBBOX:function(decimal, reverseAxisOrder) {
        if (decimal== null) {
            decimal = 6; 
        }
        var mult = Math.pow(10, decimal);
        var xmin = Math.round(this.left * mult) / mult;
        var ymin = Math.round(this.bottom * mult) / mult;
        var xmax = Math.round(this.right * mult) / mult;
        var ymax = Math.round(this.top * mult) / mult;
        if (reverseAxisOrder === true) {
            return ymin + "," + xmin + "," + ymax + "," + xmax;
        } else {
            return xmin + "," + ymin + "," + xmax + "," + ymax;
        }
    },
 
    /**
     * APIMethod: toGeometry
     * Create a new polygon geometry based on this bounds.
     *
     * Returns:
     * {<OpenLayers.Geometry.Polygon>} A new polygon with the coordinates
     *     of this bounds.
     */
    toGeometry: function() {
        return new OpenLayers.Geometry.Polygon([
            new OpenLayers.Geometry.LinearRing([
                new OpenLayers.Geometry.Point(this.left, this.bottom),
                new OpenLayers.Geometry.Point(this.right, this.bottom),
                new OpenLayers.Geometry.Point(this.right, this.top),
                new OpenLayers.Geometry.Point(this.left, this.top)
            ])
        ]);
    },
    
    /**
     * APIMethod: getWidth
     * Returns the width of the bounds.
     * 
     * Returns:
     * {Float} The width of the bounds (right minus left).
     */
    getWidth:function() {
        return (this.right - this.left);
    },

    /**
     * APIMethod: getHeight
     * Returns the height of the bounds.
     * 
     * Returns:
     * {Float} The height of the bounds (top minus bottom).
     */
    getHeight:function() {
        return (this.top - this.bottom);
    },

    /**
     * APIMethod: getSize
     * Returns an <OpenLayers.Size> object of the bounds.
     * 
     * Returns:
     * {<OpenLayers.Size>} The size of the bounds.
     */
    getSize:function() {
        return new OpenLayers.Size(this.getWidth(), this.getHeight());
    },

    /**
     * APIMethod: getCenterPixel
     * Returns the <OpenLayers.Pixel> object which represents the center of the
     *     bounds.
     * 
     * Returns:
     * {<OpenLayers.Pixel>} The center of the bounds in pixel space.
     */
    getCenterPixel:function() {
        return new OpenLayers.Pixel( (this.left + this.right) / 2,
                                     (this.bottom + this.top) / 2);
    },

    /**
     * APIMethod: getCenterLonLat
     * Returns the <OpenLayers.LonLat> object which represents the center of the
     *     bounds.
     *
     * Returns:
     * {<OpenLayers.LonLat>} The center of the bounds in map space.
     */
    getCenterLonLat:function() {
        if(!this.centerLonLat) {
            this.centerLonLat = new OpenLayers.LonLat(
                (this.left + this.right) / 2, (this.bottom + this.top) / 2
            );
        }
        return this.centerLonLat;
    },

    /**
     * APIMethod: scale
     * Scales the bounds around a pixel or lonlat. Note that the new 
     *     bounds may return non-integer properties, even if a pixel
     *     is passed. 
     * 
     * Parameters:
     * ratio - {Float} 
     * origin - {<OpenLayers.Pixel> or <OpenLayers.LonLat>}
     *          Default is center.
     *
     * Returns:
     * {<OpenLayers.Bounds>} A new bounds that is scaled by ratio
     *                      from origin.
     */
    scale: function(ratio, origin){
        if(origin == null){
            origin = this.getCenterLonLat();
        }
        
        var origx,origy;

        // get origin coordinates
        if(origin.CLASS_NAME == "OpenLayers.LonLat"){
            origx = origin.lon;
            origy = origin.lat;
        } else {
            origx = origin.x;
            origy = origin.y;
        }

        var left = (this.left - origx) * ratio + origx;
        var bottom = (this.bottom - origy) * ratio + origy;
        var right = (this.right - origx) * ratio + origx;
        var top = (this.top - origy) * ratio + origy;
        
        return new OpenLayers.Bounds(left, bottom, right, top);
    },

    /**
     * APIMethod: add
     * Shifts the coordinates of the bound by the given horizontal and vertical
     *     deltas.
     *
     * (start code)
     * var bounds = new OpenLayers.Bounds(0, 0, 10, 10);
     * bounds.toString();
     * // => "0,0,10,10"
     *
     * bounds.add(-1.5, 4).toString();
     * // => "-1.5,4,8.5,14"
     * (end)
     *
     * This method will throw a TypeError if it is passed null as an argument.
     *
     * Parameters:
     * x - {Float} horizontal delta
     * y - {Float} vertical delta
     *
     * Returns:
     * {<OpenLayers.Bounds>} A new bounds whose coordinates are the same as
     *     this, but shifted by the passed-in x and y values.
     */
    add:function(x, y) {
        if ( (x == null) || (y == null) ) {
            throw new TypeError('Bounds.add cannot receive null values');
        }
        return new OpenLayers.Bounds(this.left + x, this.bottom + y,
                                     this.right + x, this.top + y);
    },
    
    /**
     * APIMethod: extend
     * Extend the bounds to include the <OpenLayers.LonLat>,
     *     <OpenLayers.Geometry.Point> or <OpenLayers.Bounds> specified.
     *
     * Please note that this function assumes that left < right and
     *     bottom < top.
     *
     * Parameters:
     * object - {<OpenLayers.LonLat>, <OpenLayers.Geometry.Point> or
     *     <OpenLayers.Bounds>} The object to be included in the new bounds
     *     object.
     */
    extend:function(object) {
        if (object) {
            switch(object.CLASS_NAME) {
                case "OpenLayers.LonLat":
                    this.extendXY(object.lon, object.lat);
                    break;
                case "OpenLayers.Geometry.Point":
                    this.extendXY(object.x, object.y);
                    break;

                case "OpenLayers.Bounds":
                    // clear cached center location
                    this.centerLonLat = null;

                    if ( (this.left == null) || (object.left < this.left)) {
                        this.left = object.left;
                    }
                    if ( (this.bottom == null) || (object.bottom < this.bottom) ) {
                        this.bottom = object.bottom;
                    }
                    if ( (this.right == null) || (object.right > this.right) ) {
                        this.right = object.right;
                    }
                    if ( (this.top == null) || (object.top > this.top) ) {
                        this.top = object.top;
                    }
                    break;
            }
        }
    },

    /**
     * APIMethod: extendXY
     * Extend the bounds to include the XY coordinate specified.
     *
     * Parameters:
     * x - {number} The X part of the the coordinate.
     * y - {number} The Y part of the the coordinate.
     */
    extendXY:function(x, y) {
        // clear cached center location
        this.centerLonLat = null;

        if ((this.left == null) || (x < this.left)) {
            this.left = x;
        }
        if ((this.bottom == null) || (y < this.bottom)) {
            this.bottom = y;
        }
        if ((this.right == null) || (x > this.right)) {
            this.right = x;
        }
        if ((this.top == null) || (y > this.top)) {
            this.top = y;
        }
    },

    /**
     * APIMethod: containsLonLat
     * Returns whether the bounds object contains the given <OpenLayers.LonLat>.
     * 
     * Parameters:
     * ll - {<OpenLayers.LonLat>|Object} OpenLayers.LonLat or an
     *     object with a 'lon' and 'lat' properties.
     * options - {Object} Optional parameters
     *
     * Acceptable options:
     * inclusive - {Boolean} Whether or not to include the border.
     *     Default is true.
     * worldBounds - {<OpenLayers.Bounds>} If a worldBounds is provided, the
     *     ll will be considered as contained if it exceeds the world bounds,
     *     but can be wrapped around the dateline so it is contained by this
     *     bounds.
     *
     * Returns:
     * {Boolean} The passed-in lonlat is within this bounds.
     */
    containsLonLat: function(ll, options) {
        if (typeof options === "boolean") {
            options =  {inclusive: options};
        }
        options = options || {};
        var contains = this.contains(ll.lon, ll.lat, options.inclusive),
            worldBounds = options.worldBounds;
        if (worldBounds && !contains) {
            var worldWidth = worldBounds.getWidth();
            var worldCenterX = (worldBounds.left + worldBounds.right) / 2;
            var worldsAway = Math.round((ll.lon - worldCenterX) / worldWidth);
            contains = this.containsLonLat({
                lon: ll.lon - worldsAway * worldWidth,
                lat: ll.lat
            }, {inclusive: options.inclusive});
        }
        return contains;
    },

    /**
     * APIMethod: containsPixel
     * Returns whether the bounds object contains the given <OpenLayers.Pixel>.
     * 
     * Parameters:
     * px - {<OpenLayers.Pixel>}
     * inclusive - {Boolean} Whether or not to include the border. Default is
     *     true.
     *
     * Returns:
     * {Boolean} The passed-in pixel is within this bounds.
     */
    containsPixel:function(px, inclusive) {
        return this.contains(px.x, px.y, inclusive);
    },
    
    /**
     * APIMethod: contains
     * Returns whether the bounds object contains the given x and y.
     * 
     * Parameters:
     * x - {Float}
     * y - {Float}
     * inclusive - {Boolean} Whether or not to include the border. Default is
     *     true.
     *
     * Returns:
     * {Boolean} Whether or not the passed-in coordinates are within this
     *     bounds.
     */
    contains:function(x, y, inclusive) {
        //set default
        if (inclusive == null) {
            inclusive = true;
        }

        if (x == null || y == null) {
            return false;
        }

        x = OpenLayers.Util.toFloat(x);
        y = OpenLayers.Util.toFloat(y);

        var contains = false;
        if (inclusive) {
            contains = ((x >= this.left) && (x <= this.right) && 
                        (y >= this.bottom) && (y <= this.top));
        } else {
            contains = ((x > this.left) && (x < this.right) && 
                        (y > this.bottom) && (y < this.top));
        }              
        return contains;
    },

    /**
     * APIMethod: intersectsBounds
     * Determine whether the target bounds intersects this bounds.  Bounds are
     *     considered intersecting if any of their edges intersect or if one
     *     bounds contains the other.
     * 
     * Parameters:
     * bounds - {<OpenLayers.Bounds>} The target bounds.
     * options - {Object} Optional parameters.
     * 
     * Acceptable options:
     * inclusive - {Boolean} Treat coincident borders as intersecting.  Default
     *     is true.  If false, bounds that do not overlap but only touch at the
     *     border will not be considered as intersecting.
     * worldBounds - {<OpenLayers.Bounds>} If a worldBounds is provided, two
     *     bounds will be considered as intersecting if they intersect when 
     *     shifted to within the world bounds.  This applies only to bounds that
     *     cross or are completely outside the world bounds.
     *
     * Returns:
     * {Boolean} The passed-in bounds object intersects this bounds.
     */
    intersectsBounds:function(bounds, options) {
        if (typeof options === "boolean") {
            options =  {inclusive: options};
        }
        options = options || {};
        if (options.worldBounds) {
            var self = this.wrapDateLine(options.worldBounds);
            bounds = bounds.wrapDateLine(options.worldBounds);
        } else {
            self = this;
        }
        if (options.inclusive == null) {
            options.inclusive = true;
        }
        var intersects = false;
        var mightTouch = (
            self.left == bounds.right ||
            self.right == bounds.left ||
            self.top == bounds.bottom ||
            self.bottom == bounds.top
        );
        
        // if the two bounds only touch at an edge, and inclusive is false,
        // then the bounds don't *really* intersect.
        if (options.inclusive || !mightTouch) {
            // otherwise, if one of the boundaries even partially contains another,
            // inclusive of the edges, then they do intersect.
            var inBottom = (
                ((bounds.bottom >= self.bottom) && (bounds.bottom <= self.top)) ||
                ((self.bottom >= bounds.bottom) && (self.bottom <= bounds.top))
            );
            var inTop = (
                ((bounds.top >= self.bottom) && (bounds.top <= self.top)) ||
                ((self.top > bounds.bottom) && (self.top < bounds.top))
            );
            var inLeft = (
                ((bounds.left >= self.left) && (bounds.left <= self.right)) ||
                ((self.left >= bounds.left) && (self.left <= bounds.right))
            );
            var inRight = (
                ((bounds.right >= self.left) && (bounds.right <= self.right)) ||
                ((self.right >= bounds.left) && (self.right <= bounds.right))
            );
            intersects = ((inBottom || inTop) && (inLeft || inRight));
        }
        // document me
        if (options.worldBounds && !intersects) {
            var world = options.worldBounds;
            var width = world.getWidth();
            var selfCrosses = !world.containsBounds(self);
            var boundsCrosses = !world.containsBounds(bounds);
            if (selfCrosses && !boundsCrosses) {
                bounds = bounds.add(-width, 0);
                intersects = self.intersectsBounds(bounds, {inclusive: options.inclusive});
            } else if (boundsCrosses && !selfCrosses) {
                self = self.add(-width, 0);
                intersects = bounds.intersectsBounds(self, {inclusive: options.inclusive});                
            }
        }
        return intersects;
    },
    
    /**
     * APIMethod: containsBounds
     * Returns whether the bounds object contains the given <OpenLayers.Bounds>.
     * 
     * bounds - {<OpenLayers.Bounds>} The target bounds.
     * partial - {Boolean} If any of the target corners is within this bounds
     *     consider the bounds contained.  Default is false.  If false, the
     *     entire target bounds must be contained within this bounds.
     * inclusive - {Boolean} Treat shared edges as contained.  Default is
     *     true.
     *
     * Returns:
     * {Boolean} The passed-in bounds object is contained within this bounds. 
     */
    containsBounds:function(bounds, partial, inclusive) {
        if (partial == null) {
            partial = false;
        }
        if (inclusive == null) {
            inclusive = true;
        }
        var bottomLeft  = this.contains(bounds.left, bounds.bottom, inclusive);
        var bottomRight = this.contains(bounds.right, bounds.bottom, inclusive);
        var topLeft  = this.contains(bounds.left, bounds.top, inclusive);
        var topRight = this.contains(bounds.right, bounds.top, inclusive);
        
        return (partial) ? (bottomLeft || bottomRight || topLeft || topRight)
                         : (bottomLeft && bottomRight && topLeft && topRight);
    },

    /** 
     * APIMethod: determineQuadrant
     * Returns the the quadrant ("br", "tr", "tl", "bl") in which the given
     *     <OpenLayers.LonLat> lies.
     *
     * Parameters:
     * lonlat - {<OpenLayers.LonLat>}
     *
     * Returns:
     * {String} The quadrant ("br" "tr" "tl" "bl") of the bounds in which the
     *     coordinate lies.
     */
    determineQuadrant: function(lonlat) {
    
        var quadrant = "";
        var center = this.getCenterLonLat();
        
        quadrant += (lonlat.lat < center.lat) ? "b" : "t";
        quadrant += (lonlat.lon < center.lon) ? "l" : "r";
    
        return quadrant; 
    },
    
    /**
     * APIMethod: transform
     * Transform the Bounds object from source to dest. 
     *
     * Parameters: 
     * source - {<OpenLayers.Projection>} Source projection. 
     * dest   - {<OpenLayers.Projection>} Destination projection. 
     *
     * Returns:
     * {<OpenLayers.Bounds>} Itself, for use in chaining operations.
     */
    transform: function(source, dest) {
        // clear cached center location
        this.centerLonLat = null;
        var ll = OpenLayers.Projection.transform(
            {'x': this.left, 'y': this.bottom}, source, dest);
        var lr = OpenLayers.Projection.transform(
            {'x': this.right, 'y': this.bottom}, source, dest);
        var ul = OpenLayers.Projection.transform(
            {'x': this.left, 'y': this.top}, source, dest);
        var ur = OpenLayers.Projection.transform(
            {'x': this.right, 'y': this.top}, source, dest);
        this.left   = Math.min(ll.x, ul.x);
        this.bottom = Math.min(ll.y, lr.y);
        this.right  = Math.max(lr.x, ur.x);
        this.top    = Math.max(ul.y, ur.y);
        return this;
    },

    /**
     * APIMethod: wrapDateLine
     * Wraps the bounds object around the dateline.
     *  
     * Parameters:
     * maxExtent - {<OpenLayers.Bounds>}
     * options - {Object} Some possible options are:
     *
     * Allowed Options:
     *                    leftTolerance - {float} Allow for a margin of error 
     *                                            with the 'left' value of this 
     *                                            bound.
     *                                            Default is 0.
     *                    rightTolerance - {float} Allow for a margin of error 
     *                                             with the 'right' value of 
     *                                             this bound.
     *                                             Default is 0.
     * 
     * Returns:
     * {<OpenLayers.Bounds>} A copy of this bounds, but wrapped around the 
     *                       "dateline" (as specified by the borders of 
     *                       maxExtent). Note that this function only returns 
     *                       a different bounds value if this bounds is 
     *                       *entirely* outside of the maxExtent. If this 
     *                       bounds straddles the dateline (is part in/part 
     *                       out of maxExtent), the returned bounds will always 
     *                       cross the left edge of the given maxExtent.
     *.
     */
    wrapDateLine: function(maxExtent, options) {    
        options = options || {};
        
        var leftTolerance = options.leftTolerance || 0;
        var rightTolerance = options.rightTolerance || 0;

        var newBounds = this.clone();
    
        if (maxExtent) {
            var width = maxExtent.getWidth();

            //shift right?
            while (newBounds.left < maxExtent.left && 
                   newBounds.right - rightTolerance <= maxExtent.left ) { 
                newBounds = newBounds.add(width, 0);
            }

            //shift left?
            while (newBounds.left + leftTolerance >= maxExtent.right && 
                   newBounds.right > maxExtent.right ) { 
                newBounds = newBounds.add(-width, 0);
            }
           
            // crosses right only? force left
            var newLeft = newBounds.left + leftTolerance;
            if (newLeft < maxExtent.right && newLeft > maxExtent.left && 
                   newBounds.right - rightTolerance > maxExtent.right) {
                newBounds = newBounds.add(-width, 0);
            }
        }
                
        return newBounds;
    },

    CLASS_NAME: "OpenLayers.Bounds"
});

/** 
 * APIFunction: fromString
 * Alternative constructor that builds a new OpenLayers.Bounds from a 
 *     parameter string.
 *
 * (begin code)
 * OpenLayers.Bounds.fromString("5,42,10,45");
 * // => equivalent to ...
 * new OpenLayers.Bounds(5, 42, 10, 45);
 * (end)
 *
 * Parameters: 
 * str - {String} Comma-separated bounds string. (e.g. "5,42,10,45")
 * reverseAxisOrder - {Boolean} Does the string use reverse axis order?
 *
 * Returns:
 * {<OpenLayers.Bounds>} New bounds object built from the 
 *                       passed-in String.
 */
OpenLayers.Bounds.fromString = function(str, reverseAxisOrder) {
    var bounds = str.split(",");
    return OpenLayers.Bounds.fromArray(bounds, reverseAxisOrder);
};

/** 
 * APIFunction: fromArray
 * Alternative constructor that builds a new OpenLayers.Bounds from an array.
 *
 * (begin code)
 * OpenLayers.Bounds.fromArray( [5, 42, 10, 45] );
 * // => equivalent to ...
 * new OpenLayers.Bounds(5, 42, 10, 45);
 * (end)
 *
 * Parameters:
 * bbox - {Array(Float)} Array of bounds values (e.g. [5,42,10,45])
 * reverseAxisOrder - {Boolean} Does the array use reverse axis order?
 *
 * Returns:
 * {<OpenLayers.Bounds>} New bounds object built from the passed-in Array.
 */
OpenLayers.Bounds.fromArray = function(bbox, reverseAxisOrder) {
    return reverseAxisOrder === true ?
           new OpenLayers.Bounds(bbox[1], bbox[0], bbox[3], bbox[2]) :
           new OpenLayers.Bounds(bbox[0], bbox[1], bbox[2], bbox[3]);
};

/** 
 * APIFunction: fromSize
 * Alternative constructor that builds a new OpenLayers.Bounds from a size.
 *
 * (begin code)
 * OpenLayers.Bounds.fromSize( new OpenLayers.Size(10, 20) );
 * // => equivalent to ...
 * new OpenLayers.Bounds(0, 20, 10, 0);
 * (end)
 *
 * Parameters:
 * size - {<OpenLayers.Size> or Object} <OpenLayers.Size> or an object with
 *     both 'w' and 'h' properties.
 *
 * Returns:
 * {<OpenLayers.Bounds>} New bounds object built from the passed-in size.
 */
OpenLayers.Bounds.fromSize = function(size) {
    return new OpenLayers.Bounds(0,
                                 size.h,
                                 size.w,
                                 0);
};

/**
 * Function: oppositeQuadrant
 * Get the opposite quadrant for a given quadrant string.
 *
 * (begin code)
 * OpenLayers.Bounds.oppositeQuadrant( "tl" );
 * // => "br"
 *
 * OpenLayers.Bounds.oppositeQuadrant( "tr" );
 * // => "bl"
 * (end)
 *
 * Parameters:
 * quadrant - {String} two character quadrant shortstring
 *
 * Returns:
 * {String} The opposing quadrant ("br" "tr" "tl" "bl"). For Example, if 
 *          you pass in "bl" it returns "tr", if you pass in "br" it 
 *          returns "tl", etc.
 */
OpenLayers.Bounds.oppositeQuadrant = function(quadrant) {
    var opp = "";
    
    opp += (quadrant.charAt(0) == 't') ? 'b' : 't';
    opp += (quadrant.charAt(1) == 'l') ? 'r' : 'l';
    
    return opp;
};
/* ======================================================================
    OpenLayers/BaseTypes/Element.js
   ====================================================================== */

/* Copyright (c) 2006-2013 by OpenLayers Contributors (see authors.txt for
 * full list of contributors). Published under the 2-clause BSD license.
 * See license.txt in the OpenLayers distribution or repository for the
 * full text of the license. */

/**
 * @requires OpenLayers/Util.js
 * @requires OpenLayers/BaseTypes.js
 */

/**
 * Namespace: OpenLayers.Element
 */
OpenLayers.Element = {

    /**
     * APIFunction: visible
     * 
     * Parameters: 
     * element - {DOMElement}
     * 
     * Returns:
     * {Boolean} Is the element visible?
     */
    visible: function(element) {
        return OpenLayers.Util.getElement(element).style.display != 'none';
    },

    /**
     * APIFunction: toggle
     * Toggle the visibility of element(s) passed in
     * 
     * Parameters:
     * element - {DOMElement} Actually user can pass any number of elements
     */
    toggle: function() {
        for (var i=0, len=arguments.length; i<len; i++) {
            var element = OpenLayers.Util.getElement(arguments[i]);
            var display = OpenLayers.Element.visible(element) ? 'none' 
                                                              : '';
            element.style.display = display;
        }
    },

    /**
     * APIFunction: remove
     * Remove the specified element from the DOM.
     * 
     * Parameters:
     * element - {DOMElement}
     */
    remove: function(element) {
        element = OpenLayers.Util.getElement(element);
        element.parentNode.removeChild(element);
    },

    /**
     * APIFunction: getHeight
     *  
     * Parameters:
     * element - {DOMElement}
     * 
     * Returns:
     * {Integer} The offset height of the element passed in
     */
    getHeight: function(element) {
        element = OpenLayers.Util.getElement(element);
        return element.offsetHeight;
    },

    /**
     * Function: hasClass
     * Tests if an element has the given CSS class name.
     *
     * Parameters:
     * element - {DOMElement} A DOM element node.
     * name - {String} The CSS class name to search for.
     *
     * Returns:
     * {Boolean} The element has the given class name.
     */
    hasClass: function(element, name) {
        var names = element.className;
        return (!!names && new RegExp("(^|\\s)" + name + "(\\s|$)").test(names));
    },
    
    /**
     * Function: addClass
     * Add a CSS class name to an element.  Safe where element already has
     *     the class name.
     *
     * Parameters:
     * element - {DOMElement} A DOM element node.
     * name - {String} The CSS class name to add.
     *
     * Returns:
     * {DOMElement} The element.
     */
    addClass: function(element, name) {
        if(!OpenLayers.Element.hasClass(element, name)) {
            element.className += (element.className ? " " : "") + name;
        }
        return element;
    },

    /**
     * Function: removeClass
     * Remove a CSS class name from an element.  Safe where element does not
     *     have the class name.
     *
     * Parameters:
     * element - {DOMElement} A DOM element node.
     * name - {String} The CSS class name to remove.
     *
     * Returns:
     * {DOMElement} The element.
     */
    removeClass: function(element, name) {
        var names = element.className;
        if(names) {
            element.className = OpenLayers.String.trim(
                names.replace(
                    new RegExp("(^|\\s+)" + name + "(\\s+|$)"), " "
                )
            );
        }
        return element;
    },

    /**
     * Function: toggleClass
     * Remove a CSS class name from an element if it exists.  Add the class name
     *     if it doesn't exist.
     *
     * Parameters:
     * element - {DOMElement} A DOM element node.
     * name - {String} The CSS class name to toggle.
     *
     * Returns:
     * {DOMElement} The element.
     */
    toggleClass: function(element, name) {
        if(OpenLayers.Element.hasClass(element, name)) {
            OpenLayers.Element.removeClass(element, name);
        } else {
            OpenLayers.Element.addClass(element, name);
        }
        return element;
    },

    /**
     * APIFunction: getStyle
     * 
     * Parameters:
     * element - {DOMElement}
     * style - {?}
     * 
     * Returns:
     * {?}
     */
    getStyle: function(element, style) {
        element = OpenLayers.Util.getElement(element);

        var value = null;
        if (element && element.style) {
            value = element.style[OpenLayers.String.camelize(style)];
            if (!value) {
                if (document.defaultView && 
                    document.defaultView.getComputedStyle) {
                    
                    var css = document.defaultView.getComputedStyle(element, null);
                    value = css ? css.getPropertyValue(style) : null;
                } else if (element.currentStyle) {
                    value = element.currentStyle[OpenLayers.String.camelize(style)];
                }
            }
        
            var positions = ['left', 'top', 'right', 'bottom'];
            if (window.opera &&
                (OpenLayers.Util.indexOf(positions,style) != -1) &&
                (OpenLayers.Element.getStyle(element, 'position') == 'static')) { 
                value = 'auto';
            }
        }
    
        return value == 'auto' ? null : value;
    }

};
/* ======================================================================
    OpenLayers/BaseTypes/LonLat.js
   ====================================================================== */

/* Copyright (c) 2006-2013 by OpenLayers Contributors (see authors.txt for
 * full list of contributors). Published under the 2-clause BSD license.
 * See license.txt in the OpenLayers distribution or repository for the
 * full text of the license. */

/**
 * @requires OpenLayers/BaseTypes/Class.js
 */

/**
 * Class: OpenLayers.LonLat
 * This class represents a longitude and latitude pair
 */
OpenLayers.LonLat = OpenLayers.Class({

    /** 
     * APIProperty: lon
     * {Float} The x-axis coodinate in map units
     */
    lon: 0.0,
    
    /** 
     * APIProperty: lat
     * {Float} The y-axis coordinate in map units
     */
    lat: 0.0,

    /**
     * Constructor: OpenLayers.LonLat
     * Create a new map location. Coordinates can be passed either as two
     * arguments, or as a single argument.
     *
     * Parameters (two arguments):
     * lon - {Number} The x-axis coordinate in map units.  If your map is in
     *     a geographic projection, this will be the Longitude.  Otherwise,
     *     it will be the x coordinate of the map location in your map units.
     * lat - {Number} The y-axis coordinate in map units.  If your map is in
     *     a geographic projection, this will be the Latitude.  Otherwise,
     *     it will be the y coordinate of the map location in your map units.
     *
     * Parameters (single argument):
     * location - {Array(Float)} [lon, lat]
     */
    initialize: function(lon, lat) {
        if (OpenLayers.Util.isArray(lon)) {
            lat = lon[1];
            lon = lon[0];
        }
        this.lon = OpenLayers.Util.toFloat(lon);
        this.lat = OpenLayers.Util.toFloat(lat);
    },
    
    /**
     * Method: toString
     * Return a readable string version of the lonlat
     *
     * Returns:
     * {String} String representation of OpenLayers.LonLat object. 
     *           (e.g. <i>"lon=5,lat=42"</i>)
     */
    toString:function() {
        return ("lon=" + this.lon + ",lat=" + this.lat);
    },

    /** 
     * APIMethod: toShortString
     * 
     * Returns:
     * {String} Shortened String representation of OpenLayers.LonLat object. 
     *         (e.g. <i>"5, 42"</i>)
     */
    toShortString:function() {
        return (this.lon + ", " + this.lat);
    },

    /** 
     * APIMethod: clone
     * 
     * Returns:
     * {<OpenLayers.LonLat>} New OpenLayers.LonLat object with the same lon 
     *                       and lat values
     */
    clone:function() {
        return new OpenLayers.LonLat(this.lon, this.lat);
    },

    /** 
     * APIMethod: add
     * 
     * Parameters:
     * lon - {Float}
     * lat - {Float}
     * 
     * Returns:
     * {<OpenLayers.LonLat>} A new OpenLayers.LonLat object with the lon and 
     *                       lat passed-in added to this's. 
     */
    add:function(lon, lat) {
        if ( (lon == null) || (lat == null) ) {
            throw new TypeError('LonLat.add cannot receive null values');
        }
        return new OpenLayers.LonLat(this.lon + OpenLayers.Util.toFloat(lon), 
                                     this.lat + OpenLayers.Util.toFloat(lat));
    },

    /** 
     * APIMethod: equals
     * 
     * Parameters:
     * ll - {<OpenLayers.LonLat>}
     * 
     * Returns:
     * {Boolean} Boolean value indicating whether the passed-in 
     *           <OpenLayers.LonLat> object has the same lon and lat 
     *           components as this.
     *           Note: if ll passed in is null, returns false
     */
    equals:function(ll) {
        var equals = false;
        if (ll != null) {
            equals = ((this.lon == ll.lon && this.lat == ll.lat) ||
                      (isNaN(this.lon) && isNaN(this.lat) && isNaN(ll.lon) && isNaN(ll.lat)));
        }
        return equals;
    },

    /**
     * APIMethod: transform
     * Transform the LonLat object from source to dest. This transformation is
     *    *in place*: if you want a *new* lonlat, use .clone() first.
     *
     * Parameters: 
     * source - {<OpenLayers.Projection>} Source projection. 
     * dest   - {<OpenLayers.Projection>} Destination projection. 
     *
     * Returns:
     * {<OpenLayers.LonLat>} Itself, for use in chaining operations.
     */
    transform: function(source, dest) {
        var point = OpenLayers.Projection.transform(
            {'x': this.lon, 'y': this.lat}, source, dest);
        this.lon = point.x;
        this.lat = point.y;
        return this;
    },
    
    /**
     * APIMethod: wrapDateLine
     * 
     * Parameters:
     * maxExtent - {<OpenLayers.Bounds>}
     * 
     * Returns:
     * {<OpenLayers.LonLat>} A copy of this lonlat, but wrapped around the 
     *                       "dateline" (as specified by the borders of 
     *                       maxExtent)
     */
    wrapDateLine: function(maxExtent) {    

        var newLonLat = this.clone();
    
        if (maxExtent) {
            //shift right?
            while (newLonLat.lon < maxExtent.left) {
                newLonLat.lon +=  maxExtent.getWidth();
            }    
           
            //shift left?
            while (newLonLat.lon > maxExtent.right) {
                newLonLat.lon -= maxExtent.getWidth();
            }    
        }
                
        return newLonLat;
    },

    CLASS_NAME: "OpenLayers.LonLat"
});

/** 
 * Function: fromString
 * Alternative constructor that builds a new <OpenLayers.LonLat> from a 
 *     parameter string
 * 
 * Parameters:
 * str - {String} Comma-separated Lon,Lat coordinate string. 
 *                 (e.g. <i>"5,40"</i>)
 * 
 * Returns:
 * {<OpenLayers.LonLat>} New <OpenLayers.LonLat> object built from the 
 *                       passed-in String.
 */
OpenLayers.LonLat.fromString = function(str) {
    var pair = str.split(",");
    return new OpenLayers.LonLat(pair[0], pair[1]);
};

/** 
 * Function: fromArray
 * Alternative constructor that builds a new <OpenLayers.LonLat> from an 
 *     array of two numbers that represent lon- and lat-values.
 * 
 * Parameters:
 * arr - {Array(Float)} Array of lon/lat values (e.g. [5,-42])
 * 
 * Returns:
 * {<OpenLayers.LonLat>} New <OpenLayers.LonLat> object built from the 
 *                       passed-in array.
 */
OpenLayers.LonLat.fromArray = function(arr) {
    var gotArr = OpenLayers.Util.isArray(arr),
        lon = gotArr && arr[0],
        lat = gotArr && arr[1];
    return new OpenLayers.LonLat(lon, lat);
};
/* ======================================================================
    OpenLayers/BaseTypes/Pixel.js
   ====================================================================== */

/* Copyright (c) 2006-2013 by OpenLayers Contributors (see authors.txt for
 * full list of contributors). Published under the 2-clause BSD license.
 * See license.txt in the OpenLayers distribution or repository for the
 * full text of the license. */

/**
 * @requires OpenLayers/BaseTypes/Class.js
 */

/**
 * Class: OpenLayers.Pixel
 * This class represents a screen coordinate, in x and y coordinates
 */
OpenLayers.Pixel = OpenLayers.Class({
    
    /**
     * APIProperty: x
     * {Number} The x coordinate
     */
    x: 0.0,

    /**
     * APIProperty: y
     * {Number} The y coordinate
     */
    y: 0.0,
    
    /**
     * Constructor: OpenLayers.Pixel
     * Create a new OpenLayers.Pixel instance
     *
     * Parameters:
     * x - {Number} The x coordinate
     * y - {Number} The y coordinate
     *
     * Returns:
     * An instance of OpenLayers.Pixel
     */
    initialize: function(x, y) {
        this.x = parseFloat(x);
        this.y = parseFloat(y);
    },
    
    /**
     * Method: toString
     * Cast this object into a string
     *
     * Returns:
     * {String} The string representation of Pixel. ex: "x=200.4,y=242.2"
     */
    toString:function() {
        return ("x=" + this.x + ",y=" + this.y);
    },

    /**
     * APIMethod: clone
     * Return a clone of this pixel object
     *
     * Returns:
     * {<OpenLayers.Pixel>} A clone pixel
     */
    clone:function() {
        return new OpenLayers.Pixel(this.x, this.y); 
    },
    
    /**
     * APIMethod: equals
     * Determine whether one pixel is equivalent to another
     *
     * Parameters:
     * px - {<OpenLayers.Pixel>|Object} An OpenLayers.Pixel or an object with
     *                                  a 'x' and 'y' properties.
     *
     * Returns:
     * {Boolean} The point passed in as parameter is equal to this. Note that
     * if px passed in is null, returns false.
     */
    equals:function(px) {
        var equals = false;
        if (px != null) {
            equals = ((this.x == px.x && this.y == px.y) ||
                      (isNaN(this.x) && isNaN(this.y) && isNaN(px.x) && isNaN(px.y)));
        }
        return equals;
    },

    /**
     * APIMethod: distanceTo
     * Returns the distance to the pixel point passed in as a parameter.
     *
     * Parameters:
     * px - {<OpenLayers.Pixel>}
     *
     * Returns:
     * {Float} The pixel point passed in as parameter to calculate the
     *     distance to.
     */
    distanceTo:function(px) {
        return Math.sqrt(
            Math.pow(this.x - px.x, 2) +
            Math.pow(this.y - px.y, 2)
        );
    },

    /**
     * APIMethod: add
     *
     * Parameters:
     * x - {Integer}
     * y - {Integer}
     *
     * Returns:
     * {<OpenLayers.Pixel>} A new Pixel with this pixel's x&y augmented by the 
     * values passed in.
     */
    add:function(x, y) {
        if ( (x == null) || (y == null) ) {
            throw new TypeError('Pixel.add cannot receive null values');
        }
        return new OpenLayers.Pixel(this.x + x, this.y + y);
    },

    /**
    * APIMethod: offset
    * 
    * Parameters
    * px - {<OpenLayers.Pixel>|Object} An OpenLayers.Pixel or an object with
    *                                  a 'x' and 'y' properties.
    * 
    * Returns:
    * {<OpenLayers.Pixel>} A new Pixel with this pixel's x&y augmented by the 
    *                      x&y values of the pixel passed in.
    */
    offset:function(px) {
        var newPx = this.clone();
        if (px) {
            newPx = this.add(px.x, px.y);
        }
        return newPx;
    },

    CLASS_NAME: "OpenLayers.Pixel"
});
/* ======================================================================
    OpenLayers/BaseTypes/Size.js
   ====================================================================== */

/* Copyright (c) 2006-2013 by OpenLayers Contributors (see authors.txt for
 * full list of contributors). Published under the 2-clause BSD license.
 * See license.txt in the OpenLayers distribution or repository for the
 * full text of the license. */

/**
 * @requires OpenLayers/BaseTypes/Class.js
 */

/**
 * Class: OpenLayers.Size
 * Instances of this class represent a width/height pair
 */
OpenLayers.Size = OpenLayers.Class({

    /**
     * APIProperty: w
     * {Number} width
     */
    w: 0.0,
    
    /**
     * APIProperty: h
     * {Number} height
     */
    h: 0.0,


    /**
     * Constructor: OpenLayers.Size
     * Create an instance of OpenLayers.Size
     *
     * Parameters:
     * w - {Number} width
     * h - {Number} height
     */
    initialize: function(w, h) {
        this.w = parseFloat(w);
        this.h = parseFloat(h);
    },

    /**
     * Method: toString
     * Return the string representation of a size object
     *
     * Returns:
     * {String} The string representation of OpenLayers.Size object. 
     * (e.g. <i>"w=55,h=66"</i>)
     */
    toString:function() {
        return ("w=" + this.w + ",h=" + this.h);
    },

    /**
     * APIMethod: clone
     * Create a clone of this size object
     *
     * Returns:
     * {<OpenLayers.Size>} A new OpenLayers.Size object with the same w and h
     * values
     */
    clone:function() {
        return new OpenLayers.Size(this.w, this.h);
    },

    /**
     *
     * APIMethod: equals
     * Determine where this size is equal to another
     *
     * Parameters:
     * sz - {<OpenLayers.Size>|Object} An OpenLayers.Size or an object with
     *                                  a 'w' and 'h' properties.
     *
     * Returns: 
     * {Boolean} The passed in size has the same h and w properties as this one.
     * Note that if sz passed in is null, returns false.
     */
    equals:function(sz) {
        var equals = false;
        if (sz != null) {
            equals = ((this.w == sz.w && this.h == sz.h) ||
                      (isNaN(this.w) && isNaN(this.h) && isNaN(sz.w) && isNaN(sz.h)));
        }
        return equals;
    },

    CLASS_NAME: "OpenLayers.Size"
});
/* ======================================================================
    OpenLayers/Console.js
   ====================================================================== */

/* Copyright (c) 2006-2013 by OpenLayers Contributors (see authors.txt for
 * full list of contributors). Published under the 2-clause BSD license.
 * See license.txt in the OpenLayers distribution or repository for the
 * full text of the license. */

/**
 * @requires OpenLayers/BaseTypes/Class.js
 */

/**
 * Namespace: OpenLayers.Console
 * The OpenLayers.Console namespace is used for debugging and error logging.
 * If the Firebug Lite (../Firebug/firebug.js) is included before this script,
 * calls to OpenLayers.Console methods will get redirected to window.console.
 * This makes use of the Firebug extension where available and allows for
 * cross-browser debugging Firebug style.
 *
 * Note:
 * Note that behavior will differ with the Firebug extention and Firebug Lite.
 * Most notably, the Firebug Lite console does not currently allow for
 * hyperlinks to code or for clicking on object to explore their properties.
 * 
 */
OpenLayers.Console = {
    /**
     * Create empty functions for all console methods.  The real value of these
     * properties will be set if Firebug Lite (../Firebug/firebug.js script) is
     * included.  We explicitly require the Firebug Lite script to trigger
     * functionality of the OpenLayers.Console methods.
     */
    
    /**
     * APIFunction: log
     * Log an object in the console.  The Firebug Lite console logs string
     * representation of objects.  Given multiple arguments, they will
     * be cast to strings and logged with a space delimiter.  If the first
     * argument is a string with printf-like formatting, subsequent arguments
     * will be used in string substitution.  Any additional arguments (beyond
     * the number substituted in a format string) will be appended in a space-
     * delimited line.
     * 
     * Parameters:
     * object - {Object}
     */
    log: function() {},

    /**
     * APIFunction: debug
     * Writes a message to the console, including a hyperlink to the line
     * where it was called.
     *
     * May be called with multiple arguments as with OpenLayers.Console.log().
     * 
     * Parameters:
     * object - {Object}
     */
    debug: function() {},

    /**
     * APIFunction: info
     * Writes a message to the console with the visual "info" icon and color
     * coding and a hyperlink to the line where it was called.
     *
     * May be called with multiple arguments as with OpenLayers.Console.log().
     * 
     * Parameters:
     * object - {Object}
     */
    info: function() {},

    /**
     * APIFunction: warn
     * Writes a message to the console with the visual "warning" icon and
     * color coding and a hyperlink to the line where it was called.
     *
     * May be called with multiple arguments as with OpenLayers.Console.log().
     * 
     * Parameters:
     * object - {Object}
     */
    warn: function() {},

    /**
     * APIFunction: error
     * Writes a message to the console with the visual "error" icon and color
     * coding and a hyperlink to the line where it was called.
     *
     * May be called with multiple arguments as with OpenLayers.Console.log().
     * 
     * Parameters:
     * object - {Object}
     */
    error: function() {},
    
    /**
     * APIFunction: userError
     * A single interface for showing error messages to the user. The default
     * behavior is a Javascript alert, though this can be overridden by
     * reassigning OpenLayers.Console.userError to a different function.
     *
     * Expects a single error message
     * 
     * Parameters:
     * error - {Object}
     */
    userError: function(error) {
        alert(error);
    },

    /**
     * APIFunction: assert
     * Tests that an expression is true. If not, it will write a message to
     * the console and throw an exception.
     *
     * May be called with multiple arguments as with OpenLayers.Console.log().
     * 
     * Parameters:
     * object - {Object}
     */
    assert: function() {},

    /**
     * APIFunction: dir
     * Prints an interactive listing of all properties of the object. This
     * looks identical to the view that you would see in the DOM tab.
     * 
     * Parameters:
     * object - {Object}
     */
    dir: function() {},

    /**
     * APIFunction: dirxml
     * Prints the XML source tree of an HTML or XML element. This looks
     * identical to the view that you would see in the HTML tab. You can click
     * on any node to inspect it in the HTML tab.
     * 
     * Parameters:
     * object - {Object}
     */
    dirxml: function() {},

    /**
     * APIFunction: trace
     * Prints an interactive stack trace of JavaScript execution at the point
     * where it is called.  The stack trace details the functions on the stack,
     * as well as the values that were passed as arguments to each function.
     * You can click each function to take you to its source in the Script tab,
     * and click each argument value to inspect it in the DOM or HTML tabs.
     * 
     */
    trace: function() {},

    /**
     * APIFunction: group
     * Writes a message to the console and opens a nested block to indent all
     * future messages sent to the console. Call OpenLayers.Console.groupEnd()
     * to close the block.
     *
     * May be called with multiple arguments as with OpenLayers.Console.log().
     * 
     * Parameters:
     * object - {Object}
     */
    group: function() {},

    /**
     * APIFunction: groupEnd
     * Closes the most recently opened block created by a call to
     * OpenLayers.Console.group
     */
    groupEnd: function() {},
    
    /**
     * APIFunction: time
     * Creates a new timer under the given name. Call
     * OpenLayers.Console.timeEnd(name)
     * with the same name to stop the timer and print the time elapsed.
     *
     * Parameters:
     * name - {String}
     */
    time: function() {},

    /**
     * APIFunction: timeEnd
     * Stops a timer created by a call to OpenLayers.Console.time(name) and
     * writes the time elapsed.
     *
     * Parameters:
     * name - {String}
     */
    timeEnd: function() {},

    /**
     * APIFunction: profile
     * Turns on the JavaScript profiler. The optional argument title would
     * contain the text to be printed in the header of the profile report.
     *
     * This function is not currently implemented in Firebug Lite.
     * 
     * Parameters:
     * title - {String} Optional title for the profiler
     */
    profile: function() {},

    /**
     * APIFunction: profileEnd
     * Turns off the JavaScript profiler and prints its report.
     * 
     * This function is not currently implemented in Firebug Lite.
     */
    profileEnd: function() {},

    /**
     * APIFunction: count
     * Writes the number of times that the line of code where count was called
     * was executed. The optional argument title will print a message in
     * addition to the number of the count.
     *
     * This function is not currently implemented in Firebug Lite.
     *
     * Parameters:
     * title - {String} Optional title to be printed with count
     */
    count: function() {},

    CLASS_NAME: "OpenLayers.Console"
};

/**
 * Execute an anonymous function to extend the OpenLayers.Console namespace
 * if the firebug.js script is included.  This closure is used so that the
 * "scripts" and "i" variables don't pollute the global namespace.
 */
(function() {
    /**
     * If Firebug Lite is included (before this script), re-route all
     * OpenLayers.Console calls to the console object.
     */
    var scripts = document.getElementsByTagName("script");
    for(var i=0, len=scripts.length; i<len; ++i) {
        if(scripts[i].src.indexOf("firebug.js") != -1) {
            if(console) {
                OpenLayers.Util.extend(OpenLayers.Console, console);
                break;
            }
        }
    }
})();
/* ======================================================================
    OpenLayers/Lang.js
   ====================================================================== */

/* Copyright (c) 2006-2013 by OpenLayers Contributors (see authors.txt for
 * full list of contributors). Published under the 2-clause BSD license.
 * See license.txt in the OpenLayers distribution or repository for the
 * full text of the license. */

/**
 * @requires OpenLayers/BaseTypes.js
 * @requires OpenLayers/Console.js
 */

/**
 * Namespace: OpenLayers.Lang
 * Internationalization namespace.  Contains dictionaries in various languages
 *     and methods to set and get the current language.
 */
OpenLayers.Lang = {
    
    /** 
     * Property: code
     * {String}  Current language code to use in OpenLayers.  Use the
     *     <setCode> method to set this value and the <getCode> method to
     *     retrieve it.
     */
    code: null,

    /** 
     * APIProperty: defaultCode
     * {String} Default language to use when a specific language can't be
     *     found.  Default is "en".
     */
    defaultCode: "en",
        
    /**
     * APIFunction: getCode
     * Get the current language code.
     *
     * Returns:
     * {String} The current language code.
     */
    getCode: function() {
        if(!OpenLayers.Lang.code) {
            OpenLayers.Lang.setCode();
        }
        return OpenLayers.Lang.code;
    },
    
    /**
     * APIFunction: setCode
     * Set the language code for string translation.  This code is used by
     *     the <OpenLayers.Lang.translate> method.
     *
     * Parameters:
     * code - {String} These codes follow the IETF recommendations at
     *     http://www.ietf.org/rfc/rfc3066.txt.  If no value is set, the
     *     browser's language setting will be tested.  If no <OpenLayers.Lang>
     *     dictionary exists for the code, the <OpenLayers.String.defaultLang>
     *     will be used.
     */
    setCode: function(code) {
        var lang;
        if(!code) {
            code = (OpenLayers.BROWSER_NAME == "msie") ?
                navigator.userLanguage : navigator.language;
        }
        var parts = code.split('-');
        parts[0] = parts[0].toLowerCase();
        if(typeof OpenLayers.Lang[parts[0]] == "object") {
            lang = parts[0];
        }

        // check for regional extensions
        if(parts[1]) {
            var testLang = parts[0] + '-' + parts[1].toUpperCase();
            if(typeof OpenLayers.Lang[testLang] == "object") {
                lang = testLang;
            }
        }
        if(!lang) {
            OpenLayers.Console.warn(
                'Failed to find OpenLayers.Lang.' + parts.join("-") +
                ' dictionary, falling back to default language'
            );
            lang = OpenLayers.Lang.defaultCode;
        }
        
        OpenLayers.Lang.code = lang;
    },

    /**
     * APIMethod: translate
     * Looks up a key from a dictionary based on the current language string.
     *     The value of <getCode> will be used to determine the appropriate
     *     dictionary.  Dictionaries are stored in <OpenLayers.Lang>.
     *
     * Parameters:
     * key - {String} The key for an i18n string value in the dictionary.
     * context - {Object} Optional context to be used with
     *     <OpenLayers.String.format>.
     * 
     * Returns:
     * {String} A internationalized string.
     */
    translate: function(key, context) {
        var dictionary = OpenLayers.Lang[OpenLayers.Lang.getCode()];
        var message = dictionary && dictionary[key];
        if(!message) {
            // Message not found, fall back to message key
            message = key;
        }
        if(context) {
            message = OpenLayers.String.format(message, context);
        }
        return message;
    }
    
};


/**
 * APIMethod: OpenLayers.i18n
 * Alias for <OpenLayers.Lang.translate>.  Looks up a key from a dictionary
 *     based on the current language string. The value of
 *     <OpenLayers.Lang.getCode> will be used to determine the appropriate
 *     dictionary.  Dictionaries are stored in <OpenLayers.Lang>.
 *
 * Parameters:
 * key - {String} The key for an i18n string value in the dictionary.
 * context - {Object} Optional context to be used with
 *     <OpenLayers.String.format>.
 * 
 * Returns:
 * {String} A internationalized string.
 */
OpenLayers.i18n = OpenLayers.Lang.translate;
/* ======================================================================
    OpenLayers/Util.js
   ====================================================================== */

/* Copyright (c) 2006-2013 by OpenLayers Contributors (see authors.txt for
 * full list of contributors). Published under the 2-clause BSD license.
 * See license.txt in the OpenLayers distribution or repository for the
 * full text of the license. */

/**
 * @requires OpenLayers/BaseTypes.js
 * @requires OpenLayers/BaseTypes/Bounds.js
 * @requires OpenLayers/BaseTypes/Element.js
 * @requires OpenLayers/BaseTypes/LonLat.js
 * @requires OpenLayers/BaseTypes/Pixel.js
 * @requires OpenLayers/BaseTypes/Size.js
 * @requires OpenLayers/Lang.js
 */

/**
 * Namespace: Util
 */
OpenLayers.Util = OpenLayers.Util || {};

/** 
 * Function: getElement
 * This is the old $() from prototype
 *
 * Parameters:
 * e - {String or DOMElement or Window}
 *
 * Returns:
 * {Array(DOMElement) or DOMElement}
 */
OpenLayers.Util.getElement = function() {
    var elements = [];

    for (var i=0, len=arguments.length; i<len; i++) {
        var element = arguments[i];
        if (typeof element == 'string') {
            element = document.getElementById(element);
        }
        if (arguments.length == 1) {
            return element;
        }
        elements.push(element);
    }
    return elements;
};

/**
 * Function: isElement
 * A cross-browser implementation of "e instanceof Element".
 *
 * Parameters:
 * o - {Object} The object to test.
 *
 * Returns:
 * {Boolean}
 */
OpenLayers.Util.isElement = function(o) {
    return !!(o && o.nodeType === 1);
};

/**
 * Function: isArray
 * Tests that the provided object is an array.
 * This test handles the cross-IFRAME case not caught
 * by "a instanceof Array" and should be used instead.
 * 
 * Parameters:
 * a - {Object} the object test.
 * 
 * Returns:
 * {Boolean} true if the object is an array.
 */
OpenLayers.Util.isArray = function(a) {
    return (Object.prototype.toString.call(a) === '[object Array]');
};

/** 
 * Function: removeItem
 * Remove an object from an array. Iterates through the array
 *     to find the item, then removes it.
 *
 * Parameters:
 * array - {Array}
 * item - {Object}
 * 
 * Returns:
 * {Array} A reference to the array
 */
OpenLayers.Util.removeItem = function(array, item) {
    for(var i = array.length - 1; i >= 0; i--) {
        if(array[i] == item) {
            array.splice(i,1);
            //break;more than once??
        }
    }
    return array;
};

/** 
 * Function: indexOf
 * Seems to exist already in FF, but not in MOZ.
 * 
 * Parameters:
 * array - {Array}
 * obj - {*}
 * 
 * Returns:
 * {Integer} The index at which the first object was found in the array.
 *           If not found, returns -1.
 */
OpenLayers.Util.indexOf = function(array, obj) {
    // use the build-in function if available.
    if (typeof array.indexOf == "function") {
        return array.indexOf(obj);
    } else {
        for (var i = 0, len = array.length; i < len; i++) {
            if (array[i] == obj) {
                return i;
            }
        }
        return -1;   
    }
};


/**
 * Property: dotless
 * {RegExp}
 * Compiled regular expression to match dots (".").  This is used for replacing
 *     dots in identifiers.  Because object identifiers are frequently used for
 *     DOM element identifiers by the library, we avoid using dots to make for
 *     more sensible CSS selectors.
 *
 * TODO: Use a module pattern to avoid bloating the API with stuff like this.
 */
OpenLayers.Util.dotless = /\./g;

/**
 * Function: modifyDOMElement
 * 
 * Modifies many properties of a DOM element all at once.  Passing in 
 * null to an individual parameter will avoid setting the attribute.
 *
 * Parameters:
 * element - {DOMElement} DOM element to modify.
 * id - {String} The element id attribute to set.  Note that dots (".") will be
 *     replaced with underscore ("_") in setting the element id.
 * px - {<OpenLayers.Pixel>|Object} The element left and top position,
 *                                  OpenLayers.Pixel or an object with
 *                                  a 'x' and 'y' properties.
 * sz - {<OpenLayers.Size>|Object} The element width and height,
 *                                 OpenLayers.Size or an object with a
 *                                 'w' and 'h' properties.
 * position - {String}       The position attribute.  eg: absolute, 
 *                           relative, etc.
 * border - {String}         The style.border attribute.  eg:
 *                           solid black 2px
 * overflow - {String}       The style.overview attribute.  
 * opacity - {Float}         Fractional value (0.0 - 1.0)
 */
OpenLayers.Util.modifyDOMElement = function(element, id, px, sz, position, 
                                            border, overflow, opacity) {

    if (id) {
        element.id = id.replace(OpenLayers.Util.dotless, "_");
    }
    if (px) {
        element.style.left = px.x + "px";
        element.style.top = px.y + "px";
    }
    if (sz) {
        element.style.width = sz.w + "px";
        element.style.height = sz.h + "px";
    }
    if (position) {
        element.style.position = position;
    }
    if (border) {
        element.style.border = border;
    }
    if (overflow) {
        element.style.overflow = overflow;
    }
    if (parseFloat(opacity) >= 0.0 && parseFloat(opacity) < 1.0) {
        element.style.filter = 'alpha(opacity=' + (opacity * 100) + ')';
        element.style.opacity = opacity;
    } else if (parseFloat(opacity) == 1.0) {
        element.style.filter = '';
        element.style.opacity = '';
    }
};

/** 
 * Function: createDiv
 * Creates a new div and optionally set some standard attributes.
 * Null may be passed to each parameter if you do not wish to
 * set a particular attribute.
 * Note - zIndex is NOT set on the resulting div.
 * 
 * Parameters:
 * id - {String} An identifier for this element.  If no id is
 *               passed an identifier will be created 
 *               automatically.  Note that dots (".") will be replaced with
 *               underscore ("_") when generating ids.
 * px - {<OpenLayers.Pixel>|Object} The element left and top position,
 *                                  OpenLayers.Pixel or an object with
 *                                  a 'x' and 'y' properties.
 * sz - {<OpenLayers.Size>|Object} The element width and height,
 *                                 OpenLayers.Size or an object with a
 *                                 'w' and 'h' properties.
 * imgURL - {String} A url pointing to an image to use as a 
 *                   background image.
 * position - {String} The style.position value. eg: absolute,
 *                     relative etc.
 * border - {String} The the style.border value. 
 *                   eg: 2px solid black
 * overflow - {String} The style.overflow value. Eg. hidden
 * opacity - {Float} Fractional value (0.0 - 1.0)
 * 
 * Returns: 
 * {DOMElement} A DOM Div created with the specified attributes.
 */
OpenLayers.Util.createDiv = function(id, px, sz, imgURL, position, 
                                     border, overflow, opacity) {

    var dom = document.createElement('div');

    if (imgURL) {
        dom.style.backgroundImage = 'url(' + imgURL + ')';
    }

    //set generic properties
    if (!id) {
        id = OpenLayers.Util.createUniqueID("OpenLayersDiv");
    }
    if (!position) {
        position = "absolute";
    }
    OpenLayers.Util.modifyDOMElement(dom, id, px, sz, position, 
                                     border, overflow, opacity);

    return dom;
};

/**
 * Function: createImage
 * Creates an img element with specific attribute values.
 *  
 * Parameters:
 * id - {String} The id field for the img.  If none assigned one will be
 *               automatically generated.
 * px - {<OpenLayers.Pixel>|Object} The element left and top position,
 *                                  OpenLayers.Pixel or an object with
 *                                  a 'x' and 'y' properties.
 * sz - {<OpenLayers.Size>|Object} The element width and height,
 *                                 OpenLayers.Size or an object with a
 *                                 'w' and 'h' properties.
 * imgURL - {String} The url to use as the image source.
 * position - {String} The style.position value.
 * border - {String} The border to place around the image.
 * opacity - {Float} Fractional value (0.0 - 1.0)
 * delayDisplay - {Boolean} If true waits until the image has been
 *                          loaded.
 * 
 * Returns:
 * {DOMElement} A DOM Image created with the specified attributes.
 */
OpenLayers.Util.createImage = function(id, px, sz, imgURL, position, border,
                                       opacity, delayDisplay) {

    var image = document.createElement("img");

    //set generic properties
    if (!id) {
        id = OpenLayers.Util.createUniqueID("OpenLayersDiv");
    }
    if (!position) {
        position = "relative";
    }
    OpenLayers.Util.modifyDOMElement(image, id, px, sz, position, 
                                     border, null, opacity);

    if (delayDisplay) {
        image.style.display = "none";
        function display() {
            image.style.display = "";
            OpenLayers.Event.stopObservingElement(image);
        }
        OpenLayers.Event.observe(image, "load", display);
        OpenLayers.Event.observe(image, "error", display);
    }
    
    //set special properties
    image.style.alt = id;
    image.galleryImg = "no";
    if (imgURL) {
        image.src = imgURL;
    }
        
    return image;
};

/**
 * Property: IMAGE_RELOAD_ATTEMPTS
 * {Integer} How many times should we try to reload an image before giving up?
 *           Default is 0
 */
OpenLayers.IMAGE_RELOAD_ATTEMPTS = 0;

/**
 * Property: alphaHackNeeded
 * {Boolean} true if the png alpha hack is necessary and possible, false otherwise.
 */
OpenLayers.Util.alphaHackNeeded = null;

/**
 * Function: alphaHack
 * Checks whether it's necessary (and possible) to use the png alpha
 * hack which allows alpha transparency for png images under Internet
 * Explorer.
 * 
 * Returns:
 * {Boolean} true if the png alpha hack is necessary and possible, false otherwise.
 */
OpenLayers.Util.alphaHack = function() {
    if (OpenLayers.Util.alphaHackNeeded == null) {
        var arVersion = navigator.appVersion.split("MSIE");
        var version = parseFloat(arVersion[1]);
        var filter = false;
    
        // IEs4Lin dies when trying to access document.body.filters, because 
        // the property is there, but requires a DLL that can't be provided. This
        // means that we need to wrap this in a try/catch so that this can
        // continue.
    
        try { 
            filter = !!(document.body.filters);
        } catch (e) {}    
    
        OpenLayers.Util.alphaHackNeeded = (filter && 
                                           (version >= 5.5) && (version < 7));
    }
    return OpenLayers.Util.alphaHackNeeded;
};

/** 
 * Function: modifyAlphaImageDiv
 * 
 * Parameters:
 * div - {DOMElement} Div containing Alpha-adjusted Image
 * id - {String}
 * px - {<OpenLayers.Pixel>|Object} OpenLayers.Pixel or an object with
 *                                  a 'x' and 'y' properties.
 * sz - {<OpenLayers.Size>|Object} OpenLayers.Size or an object with
 *                                 a 'w' and 'h' properties.
 * imgURL - {String}
 * position - {String}
 * border - {String}
 * sizing - {String} 'crop', 'scale', or 'image'. Default is "scale"
 * opacity - {Float} Fractional value (0.0 - 1.0)
 */ 
OpenLayers.Util.modifyAlphaImageDiv = function(div, id, px, sz, imgURL, 
                                               position, border, sizing, 
                                               opacity) {

    OpenLayers.Util.modifyDOMElement(div, id, px, sz, position,
                                     null, null, opacity);

    var img = div.childNodes[0];

    if (imgURL) {
        img.src = imgURL;
    }
    OpenLayers.Util.modifyDOMElement(img, div.id + "_innerImage", null, sz, 
                                     "relative", border);
    
    if (OpenLayers.Util.alphaHack()) {
        if(div.style.display != "none") {
            div.style.display = "inline-block";
        }
        if (sizing == null) {
            sizing = "scale";
        }
        
        div.style.filter = "progid:DXImageTransform.Microsoft" +
                           ".AlphaImageLoader(src='" + img.src + "', " +
                           "sizingMethod='" + sizing + "')";
        if (parseFloat(div.style.opacity) >= 0.0 && 
            parseFloat(div.style.opacity) < 1.0) {
            div.style.filter += " alpha(opacity=" + div.style.opacity * 100 + ")";
        }

        img.style.filter = "alpha(opacity=0)";
    }
};

/** 
 * Function: createAlphaImageDiv
 * 
 * Parameters:
 * id - {String}
 * px - {<OpenLayers.Pixel>|Object} OpenLayers.Pixel or an object with
 *                                  a 'x' and 'y' properties.
 * sz - {<OpenLayers.Size>|Object} OpenLayers.Size or an object with
 *                                 a 'w' and 'h' properties.
 * imgURL - {String}
 * position - {String}
 * border - {String}
 * sizing - {String} 'crop', 'scale', or 'image'. Default is "scale"
 * opacity - {Float} Fractional value (0.0 - 1.0)
 * delayDisplay - {Boolean} If true waits until the image has been
 *                          loaded.
 * 
 * Returns:
 * {DOMElement} A DOM Div created with a DOM Image inside it. If the hack is 
 *              needed for transparency in IE, it is added.
 */ 
OpenLayers.Util.createAlphaImageDiv = function(id, px, sz, imgURL, 
                                               position, border, sizing, 
                                               opacity, delayDisplay) {
    
    var div = OpenLayers.Util.createDiv();
    var img = OpenLayers.Util.createImage(null, null, null, null, null, null, 
                                          null, delayDisplay);
    img.className = "olAlphaImg";
    div.appendChild(img);

    OpenLayers.Util.modifyAlphaImageDiv(div, id, px, sz, imgURL, position, 
                                        border, sizing, opacity);
    
    return div;
};


/** 
 * Function: upperCaseObject
 * Creates a new hashtable and copies over all the keys from the 
 *     passed-in object, but storing them under an uppercased
 *     version of the key at which they were stored.
 * 
 * Parameters: 
 * object - {Object}
 * 
 * Returns: 
 * {Object} A new Object with all the same keys but uppercased
 */
OpenLayers.Util.upperCaseObject = function (object) {
    var uObject = {};
    for (var key in object) {
        uObject[key.toUpperCase()] = object[key];
    }
    return uObject;
};

/** 
 * Function: applyDefaults
 * Takes an object and copies any properties that don't exist from
 *     another properties, by analogy with OpenLayers.Util.extend() from
 *     Prototype.js.
 * 
 * Parameters:
 * to - {Object} The destination object.
 * from - {Object} The source object.  Any properties of this object that
 *     are undefined in the to object will be set on the to object.
 *
 * Returns:
 * {Object} A reference to the to object.  Note that the to argument is modified
 *     in place and returned by this function.
 */
OpenLayers.Util.applyDefaults = function (to, from) {
    to = to || {};
    /*
     * FF/Windows < 2.0.0.13 reports "Illegal operation on WrappedNative
     * prototype object" when calling hawOwnProperty if the source object is an
     * instance of window.Event.
     */
    var fromIsEvt = typeof window.Event == "function"
                    && from instanceof window.Event;

    for (var key in from) {
        if (to[key] === undefined ||
            (!fromIsEvt && from.hasOwnProperty
             && from.hasOwnProperty(key) && !to.hasOwnProperty(key))) {
            to[key] = from[key];
        }
    }
    /**
     * IE doesn't include the toString property when iterating over an object's
     * properties with the for(property in object) syntax.  Explicitly check if
     * the source has its own toString property.
     */
    if(!fromIsEvt && from && from.hasOwnProperty
       && from.hasOwnProperty('toString') && !to.hasOwnProperty('toString')) {
        to.toString = from.toString;
    }
    
    return to;
};

/**
 * Function: getParameterString
 * 
 * Parameters:
 * params - {Object}
 * 
 * Returns:
 * {String} A concatenation of the properties of an object in 
 *          http parameter notation. 
 *          (ex. <i>"key1=value1&key2=value2&key3=value3"</i>)
 *          If a parameter is actually a list, that parameter will then
 *          be set to a comma-seperated list of values (foo,bar) instead
 *          of being URL escaped (foo%3Abar). 
 */
OpenLayers.Util.getParameterString = function(params) {
    var paramsArray = [];
    
    for (var key in params) {
      var value = params[key];
      if ((value != null) && (typeof value != 'function')) {
        var encodedValue;
        if (typeof value == 'object' && value.constructor == Array) {
          /* value is an array; encode items and separate with "," */
          var encodedItemArray = [];
          var item;
          for (var itemIndex=0, len=value.length; itemIndex<len; itemIndex++) {
            item = value[itemIndex];
            encodedItemArray.push(encodeURIComponent(
                (item === null || item === undefined) ? "" : item)
            );
          }
          encodedValue = encodedItemArray.join(",");
        }
        else {
          /* value is a string; simply encode */
          encodedValue = encodeURIComponent(value);
        }
        paramsArray.push(encodeURIComponent(key) + "=" + encodedValue);
      }
    }
    
    return paramsArray.join("&");
};

/**
 * Function: urlAppend
 * Appends a parameter string to a url. This function includes the logic for
 * using the appropriate character (none, & or ?) to append to the url before
 * appending the param string.
 * 
 * Parameters:
 * url - {String} The url to append to
 * paramStr - {String} The param string to append
 * 
 * Returns:
 * {String} The new url
 */
OpenLayers.Util.urlAppend = function(url, paramStr) {
    var newUrl = url;
    if(paramStr) {
        var parts = (url + " ").split(/[?&]/);
        newUrl += (parts.pop() === " " ?
            paramStr :
            parts.length ? "&" + paramStr : "?" + paramStr);
    }
    return newUrl;
};

/** 
 * Function: getImagesLocation
 * 
 * Returns:
 * {String} The fully formatted image location string
 */
OpenLayers.Util.getImagesLocation = function() {
    return OpenLayers.ImgPath || (OpenLayers._getScriptLocation() + "img/");
};

/** 
 * Function: getImageLocation
 * 
 * Returns:
 * {String} The fully formatted location string for a specified image
 */
OpenLayers.Util.getImageLocation = function(image) {
    return OpenLayers.Util.getImagesLocation() + image;
};


/** 
 * Function: Try
 * Execute functions until one of them doesn't throw an error. 
 *     Capitalized because "try" is a reserved word in JavaScript.
 *     Taken directly from OpenLayers.Util.Try()
 * 
 * Parameters:
 * [*] - {Function} Any number of parameters may be passed to Try()
 *    It will attempt to execute each of them until one of them 
 *    successfully executes. 
 *    If none executes successfully, returns null.
 * 
 * Returns:
 * {*} The value returned by the first successfully executed function.
 */
OpenLayers.Util.Try = function() {
    var returnValue = null;

    for (var i=0, len=arguments.length; i<len; i++) {
      var lambda = arguments[i];
      try {
        returnValue = lambda();
        break;
      } catch (e) {}
    }

    return returnValue;
};

/**
 * Function: getXmlNodeValue
 * 
 * Parameters:
 * node - {XMLNode}
 * 
 * Returns:
 * {String} The text value of the given node, without breaking in firefox or IE
 */
OpenLayers.Util.getXmlNodeValue = function(node) {
    var val = null;
    OpenLayers.Util.Try( 
        function() {
            val = node.text;
            if (!val) {
                val = node.textContent;
            }
            if (!val) {
                val = node.firstChild.nodeValue;
            }
        }, 
        function() {
            val = node.textContent;
        }); 
    return val;
};

/** 
 * Function: mouseLeft
 * 
 * Parameters:
 * evt - {Event}
 * div - {HTMLDivElement}
 * 
 * Returns:
 * {Boolean}
 */
OpenLayers.Util.mouseLeft = function (evt, div) {
    // start with the element to which the mouse has moved
    var target = (evt.relatedTarget) ? evt.relatedTarget : evt.toElement;
    // walk up the DOM tree.
    while (target != div && target != null) {
        target = target.parentNode;
    }
    // if the target we stop at isn't the div, then we've left the div.
    return (target != div);
};

/**
 * Property: precision
 * {Number} The number of significant digits to retain to avoid
 * floating point precision errors.
 *
 * We use 14 as a "safe" default because, although IEEE 754 double floats
 * (standard on most modern operating systems) support up to about 16
 * significant digits, 14 significant digits are sufficient to represent
 * sub-millimeter accuracy in any coordinate system that anyone is likely to
 * use with OpenLayers.
 *
 * If DEFAULT_PRECISION is set to 0, the original non-truncating behavior
 * of OpenLayers <2.8 is preserved. Be aware that this will cause problems
 * with certain projections, e.g. spherical Mercator.
 *
 */
OpenLayers.Util.DEFAULT_PRECISION = 14;

/**
 * Function: toFloat
 * Convenience method to cast an object to a Number, rounded to the
 * desired floating point precision.
 *
 * Parameters:
 * number    - {Number} The number to cast and round.
 * precision - {Number} An integer suitable for use with
 *      Number.toPrecision(). Defaults to OpenLayers.Util.DEFAULT_PRECISION.
 *      If set to 0, no rounding is performed.
 *
 * Returns:
 * {Number} The cast, rounded number.
 */
OpenLayers.Util.toFloat = function (number, precision) {
    if (precision == null) {
        precision = OpenLayers.Util.DEFAULT_PRECISION;
    }
    if (typeof number !== "number") {
        number = parseFloat(number);
    }
    return precision === 0 ? number :
                             parseFloat(number.toPrecision(precision));
};

/**
 * Function: rad
 * 
 * Parameters:
 * x - {Float}
 * 
 * Returns:
 * {Float}
 */
OpenLayers.Util.rad = function(x) {return x*Math.PI/180;};

/**
 * Function: deg
 *
 * Parameters:
 * x - {Float}
 *
 * Returns:
 * {Float}
 */
OpenLayers.Util.deg = function(x) {return x*180/Math.PI;};

/**
 * Property: VincentyConstants
 * {Object} Constants for Vincenty functions.
 */
OpenLayers.Util.VincentyConstants = {
    a: 6378137,
    b: 6356752.3142,
    f: 1/298.257223563
};

/**
 * APIFunction: distVincenty
 * Given two objects representing points with geographic coordinates, this
 *     calculates the distance between those points on the surface of an
 *     ellipsoid.
 *
 * Parameters:
 * p1 - {<OpenLayers.LonLat>} (or any object with both .lat, .lon properties)
 * p2 - {<OpenLayers.LonLat>} (or any object with both .lat, .lon properties)
 *
 * Returns:
 * {Float} The distance (in km) between the two input points as measured on an
 *     ellipsoid.  Note that the input point objects must be in geographic
 *     coordinates (decimal degrees) and the return distance is in kilometers.
 */
OpenLayers.Util.distVincenty = function(p1, p2) {
    var ct = OpenLayers.Util.VincentyConstants;
    var a = ct.a, b = ct.b, f = ct.f;

    var L = OpenLayers.Util.rad(p2.lon - p1.lon);
    var U1 = Math.atan((1-f) * Math.tan(OpenLayers.Util.rad(p1.lat)));
    var U2 = Math.atan((1-f) * Math.tan(OpenLayers.Util.rad(p2.lat)));
    var sinU1 = Math.sin(U1), cosU1 = Math.cos(U1);
    var sinU2 = Math.sin(U2), cosU2 = Math.cos(U2);
    var lambda = L, lambdaP = 2*Math.PI;
    var iterLimit = 20;
    while (Math.abs(lambda-lambdaP) > 1e-12 && --iterLimit>0) {
        var sinLambda = Math.sin(lambda), cosLambda = Math.cos(lambda);
        var sinSigma = Math.sqrt((cosU2*sinLambda) * (cosU2*sinLambda) +
        (cosU1*sinU2-sinU1*cosU2*cosLambda) * (cosU1*sinU2-sinU1*cosU2*cosLambda));
        if (sinSigma==0) {
            return 0;  // co-incident points
        }
        var cosSigma = sinU1*sinU2 + cosU1*cosU2*cosLambda;
        var sigma = Math.atan2(sinSigma, cosSigma);
        var alpha = Math.asin(cosU1 * cosU2 * sinLambda / sinSigma);
        var cosSqAlpha = Math.cos(alpha) * Math.cos(alpha);
        var cos2SigmaM = cosSigma - 2*sinU1*sinU2/cosSqAlpha;
        var C = f/16*cosSqAlpha*(4+f*(4-3*cosSqAlpha));
        lambdaP = lambda;
        lambda = L + (1-C) * f * Math.sin(alpha) *
        (sigma + C*sinSigma*(cos2SigmaM+C*cosSigma*(-1+2*cos2SigmaM*cos2SigmaM)));
    }
    if (iterLimit==0) {
        return NaN;  // formula failed to converge
    }
    var uSq = cosSqAlpha * (a*a - b*b) / (b*b);
    var A = 1 + uSq/16384*(4096+uSq*(-768+uSq*(320-175*uSq)));
    var B = uSq/1024 * (256+uSq*(-128+uSq*(74-47*uSq)));
    var deltaSigma = B*sinSigma*(cos2SigmaM+B/4*(cosSigma*(-1+2*cos2SigmaM*cos2SigmaM)-
        B/6*cos2SigmaM*(-3+4*sinSigma*sinSigma)*(-3+4*cos2SigmaM*cos2SigmaM)));
    var s = b*A*(sigma-deltaSigma);
    var d = s.toFixed(3)/1000; // round to 1mm precision
    return d;
};

/**
 * APIFunction: destinationVincenty
 * Calculate destination point given start point lat/long (numeric degrees),
 * bearing (numeric degrees) & distance (in m).
 * Adapted from Chris Veness work, see
 * http://www.movable-type.co.uk/scripts/latlong-vincenty-direct.html
 *
 * Parameters:
 * lonlat  - {<OpenLayers.LonLat>} (or any object with both .lat, .lon
 *     properties) The start point.
 * brng     - {Float} The bearing (degrees).
 * dist     - {Float} The ground distance (meters).
 *
 * Returns:
 * {<OpenLayers.LonLat>} The destination point.
 */
OpenLayers.Util.destinationVincenty = function(lonlat, brng, dist) {
    var u = OpenLayers.Util;
    var ct = u.VincentyConstants;
    var a = ct.a, b = ct.b, f = ct.f;

    var lon1 = lonlat.lon;
    var lat1 = lonlat.lat;

    var s = dist;
    var alpha1 = u.rad(brng);
    var sinAlpha1 = Math.sin(alpha1);
    var cosAlpha1 = Math.cos(alpha1);

    var tanU1 = (1-f) * Math.tan(u.rad(lat1));
    var cosU1 = 1 / Math.sqrt((1 + tanU1*tanU1)), sinU1 = tanU1*cosU1;
    var sigma1 = Math.atan2(tanU1, cosAlpha1);
    var sinAlpha = cosU1 * sinAlpha1;
    var cosSqAlpha = 1 - sinAlpha*sinAlpha;
    var uSq = cosSqAlpha * (a*a - b*b) / (b*b);
    var A = 1 + uSq/16384*(4096+uSq*(-768+uSq*(320-175*uSq)));
    var B = uSq/1024 * (256+uSq*(-128+uSq*(74-47*uSq)));

    var sigma = s / (b*A), sigmaP = 2*Math.PI;
    while (Math.abs(sigma-sigmaP) > 1e-12) {
        var cos2SigmaM = Math.cos(2*sigma1 + sigma);
        var sinSigma = Math.sin(sigma);
        var cosSigma = Math.cos(sigma);
        var deltaSigma = B*sinSigma*(cos2SigmaM+B/4*(cosSigma*(-1+2*cos2SigmaM*cos2SigmaM)-
            B/6*cos2SigmaM*(-3+4*sinSigma*sinSigma)*(-3+4*cos2SigmaM*cos2SigmaM)));
        sigmaP = sigma;
        sigma = s / (b*A) + deltaSigma;
    }

    var tmp = sinU1*sinSigma - cosU1*cosSigma*cosAlpha1;
    var lat2 = Math.atan2(sinU1*cosSigma + cosU1*sinSigma*cosAlpha1,
        (1-f)*Math.sqrt(sinAlpha*sinAlpha + tmp*tmp));
    var lambda = Math.atan2(sinSigma*sinAlpha1, cosU1*cosSigma - sinU1*sinSigma*cosAlpha1);
    var C = f/16*cosSqAlpha*(4+f*(4-3*cosSqAlpha));
    var L = lambda - (1-C) * f * sinAlpha *
        (sigma + C*sinSigma*(cos2SigmaM+C*cosSigma*(-1+2*cos2SigmaM*cos2SigmaM)));

    var revAz = Math.atan2(sinAlpha, -tmp);  // final bearing

    return new OpenLayers.LonLat(lon1+u.deg(L), u.deg(lat2));
};

/**
 * Function: getParameters
 * Parse the parameters from a URL or from the current page itself into a 
 *     JavaScript Object. Note that parameter values with commas are separated
 *     out into an Array.
 * 
 * Parameters:
 * url - {String} Optional url used to extract the query string.
 *                If url is null or is not supplied, query string is taken 
 *                from the page location.
 * options - {Object} Additional options. Optional.
 *
 * Valid options:
 *   splitArgs - {Boolean} Split comma delimited params into arrays? Default is
 *       true.
 * 
 * Returns:
 * {Object} An object of key/value pairs from the query string.
 */
OpenLayers.Util.getParameters = function(url, options) {
    options = options || {};
    // if no url specified, take it from the location bar
    url = (url === null || url === undefined) ? window.location.href : url;

    //parse out parameters portion of url string
    var paramsString = "";
    if (OpenLayers.String.contains(url, '?')) {
        var start = url.indexOf('?') + 1;
        var end = OpenLayers.String.contains(url, "#") ?
                    url.indexOf('#') : url.length;
        paramsString = url.substring(start, end);
    }

    var parameters = {};
    var pairs = paramsString.split(/[&;]/);
    for(var i=0, len=pairs.length; i<len; ++i) {
        var keyValue = pairs[i].split('=');
        if (keyValue[0]) {

            var key = keyValue[0];
            try {
                key = decodeURIComponent(key);
            } catch (err) {
                key = unescape(key);
            }
            
            // being liberal by replacing "+" with " "
            var value = (keyValue[1] || '').replace(/\+/g, " ");

            try {
                value = decodeURIComponent(value);
            } catch (err) {
                value = unescape(value);
            }
            
            // follow OGC convention of comma delimited values
            if (options.splitArgs !== false) {
                value = value.split(",");
            }

            //if there's only one value, do not return as array                    
            if (value.length == 1) {
                value = value[0];
            }                
            
            parameters[key] = value;
         }
     }
    return parameters;
};

/**
 * Property: lastSeqID
 * {Integer} The ever-incrementing count variable.
 *           Used for generating unique ids.
 */
OpenLayers.Util.lastSeqID = 0;

/**
 * Function: createUniqueID
 * Create a unique identifier for this session.  Each time this function
 *     is called, a counter is incremented.  The return will be the optional
 *     prefix (defaults to "id_") appended with the counter value.
 * 
 * Parameters:
 * prefix - {String} Optional string to prefix unique id. Default is "id_".
 *     Note that dots (".") in the prefix will be replaced with underscore ("_").
 * 
 * Returns:
 * {String} A unique id string, built on the passed in prefix.
 */
OpenLayers.Util.createUniqueID = function(prefix) {
    if (prefix == null) {
        prefix = "id_";
    } else {
        prefix = prefix.replace(OpenLayers.Util.dotless, "_");
    }
    OpenLayers.Util.lastSeqID += 1; 
    return prefix + OpenLayers.Util.lastSeqID;        
};

/**
 * Constant: INCHES_PER_UNIT
 * {Object} Constant inches per unit -- borrowed from MapServer mapscale.c
 * derivation of nautical miles from http://en.wikipedia.org/wiki/Nautical_mile
 * Includes the full set of units supported by CS-MAP (http://trac.osgeo.org/csmap/)
 * and PROJ.4 (http://trac.osgeo.org/proj/)
 * The hardcoded table is maintain in a CS-MAP source code module named CSdataU.c
 * The hardcoded table of PROJ.4 units are in pj_units.c.
 */
OpenLayers.INCHES_PER_UNIT = { 
    'inches': 1.0,
    'ft': 12.0,
    'mi': 63360.0,
    'm': 39.37,
    'km': 39370,
    'dd': 4374754,
    'yd': 36
};
OpenLayers.INCHES_PER_UNIT["in"]= OpenLayers.INCHES_PER_UNIT.inches;
OpenLayers.INCHES_PER_UNIT["degrees"] = OpenLayers.INCHES_PER_UNIT.dd;
OpenLayers.INCHES_PER_UNIT["nmi"] = 1852 * OpenLayers.INCHES_PER_UNIT.m;

// Units from CS-Map
OpenLayers.METERS_PER_INCH = 0.02540005080010160020;
OpenLayers.Util.extend(OpenLayers.INCHES_PER_UNIT, {
    "Inch": OpenLayers.INCHES_PER_UNIT.inches,
    "Meter": 1.0 / OpenLayers.METERS_PER_INCH,   //EPSG:9001
    "Foot": 0.30480060960121920243 / OpenLayers.METERS_PER_INCH,   //EPSG:9003
    "IFoot": 0.30480000000000000000 / OpenLayers.METERS_PER_INCH,   //EPSG:9002
    "ClarkeFoot": 0.3047972651151 / OpenLayers.METERS_PER_INCH,   //EPSG:9005
    "SearsFoot": 0.30479947153867624624 / OpenLayers.METERS_PER_INCH,   //EPSG:9041
    "GoldCoastFoot": 0.30479971018150881758 / OpenLayers.METERS_PER_INCH,   //EPSG:9094
    "IInch": 0.02540000000000000000 / OpenLayers.METERS_PER_INCH,
    "MicroInch": 0.00002540000000000000 / OpenLayers.METERS_PER_INCH,
    "Mil": 0.00000002540000000000 / OpenLayers.METERS_PER_INCH,
    "Centimeter": 0.01000000000000000000 / OpenLayers.METERS_PER_INCH,
    "Kilometer": 1000.00000000000000000000 / OpenLayers.METERS_PER_INCH,   //EPSG:9036
    "Yard": 0.91440182880365760731 / OpenLayers.METERS_PER_INCH,
    "SearsYard": 0.914398414616029 / OpenLayers.METERS_PER_INCH,   //EPSG:9040
    "IndianYard": 0.91439853074444079983 / OpenLayers.METERS_PER_INCH,   //EPSG:9084
    "IndianYd37": 0.91439523 / OpenLayers.METERS_PER_INCH,   //EPSG:9085
    "IndianYd62": 0.9143988 / OpenLayers.METERS_PER_INCH,   //EPSG:9086
    "IndianYd75": 0.9143985 / OpenLayers.METERS_PER_INCH,   //EPSG:9087
    "IndianFoot": 0.30479951 / OpenLayers.METERS_PER_INCH,   //EPSG:9080
    "IndianFt37": 0.30479841 / OpenLayers.METERS_PER_INCH,   //EPSG:9081
    "IndianFt62": 0.3047996 / OpenLayers.METERS_PER_INCH,   //EPSG:9082
    "IndianFt75": 0.3047995 / OpenLayers.METERS_PER_INCH,   //EPSG:9083
    "Mile": 1609.34721869443738887477 / OpenLayers.METERS_PER_INCH,
    "IYard": 0.91440000000000000000 / OpenLayers.METERS_PER_INCH,   //EPSG:9096
    "IMile": 1609.34400000000000000000 / OpenLayers.METERS_PER_INCH,   //EPSG:9093
    "NautM": 1852.00000000000000000000 / OpenLayers.METERS_PER_INCH,   //EPSG:9030
    "Lat-66": 110943.316488932731 / OpenLayers.METERS_PER_INCH,
    "Lat-83": 110946.25736872234125 / OpenLayers.METERS_PER_INCH,
    "Decimeter": 0.10000000000000000000 / OpenLayers.METERS_PER_INCH,
    "Millimeter": 0.00100000000000000000 / OpenLayers.METERS_PER_INCH,
    "Dekameter": 10.00000000000000000000 / OpenLayers.METERS_PER_INCH,
    "Decameter": 10.00000000000000000000 / OpenLayers.METERS_PER_INCH,
    "Hectometer": 100.00000000000000000000 / OpenLayers.METERS_PER_INCH,
    "GermanMeter": 1.0000135965 / OpenLayers.METERS_PER_INCH,   //EPSG:9031
    "CaGrid": 0.999738 / OpenLayers.METERS_PER_INCH,
    "ClarkeChain": 20.1166194976 / OpenLayers.METERS_PER_INCH,   //EPSG:9038
    "GunterChain": 20.11684023368047 / OpenLayers.METERS_PER_INCH,   //EPSG:9033
    "BenoitChain": 20.116782494375872 / OpenLayers.METERS_PER_INCH,   //EPSG:9062
    "SearsChain": 20.11676512155 / OpenLayers.METERS_PER_INCH,   //EPSG:9042
    "ClarkeLink": 0.201166194976 / OpenLayers.METERS_PER_INCH,   //EPSG:9039
    "GunterLink": 0.2011684023368047 / OpenLayers.METERS_PER_INCH,   //EPSG:9034
    "BenoitLink": 0.20116782494375872 / OpenLayers.METERS_PER_INCH,   //EPSG:9063
    "SearsLink": 0.2011676512155 / OpenLayers.METERS_PER_INCH,   //EPSG:9043
    "Rod": 5.02921005842012 / OpenLayers.METERS_PER_INCH,
    "IntnlChain": 20.1168 / OpenLayers.METERS_PER_INCH,   //EPSG:9097
    "IntnlLink": 0.201168 / OpenLayers.METERS_PER_INCH,   //EPSG:9098
    "Perch": 5.02921005842012 / OpenLayers.METERS_PER_INCH,
    "Pole": 5.02921005842012 / OpenLayers.METERS_PER_INCH,
    "Furlong": 201.1684023368046 / OpenLayers.METERS_PER_INCH,
    "Rood": 3.778266898 / OpenLayers.METERS_PER_INCH,
    "CapeFoot": 0.3047972615 / OpenLayers.METERS_PER_INCH,
    "Brealey": 375.00000000000000000000 / OpenLayers.METERS_PER_INCH,
    "ModAmFt": 0.304812252984505969011938 / OpenLayers.METERS_PER_INCH,
    "Fathom": 1.8288 / OpenLayers.METERS_PER_INCH,
    "NautM-UK": 1853.184 / OpenLayers.METERS_PER_INCH,
    "50kilometers": 50000.0 / OpenLayers.METERS_PER_INCH,
    "150kilometers": 150000.0 / OpenLayers.METERS_PER_INCH
});

//unit abbreviations supported by PROJ.4
OpenLayers.Util.extend(OpenLayers.INCHES_PER_UNIT, {
    "mm": OpenLayers.INCHES_PER_UNIT["Meter"] / 1000.0,
    "cm": OpenLayers.INCHES_PER_UNIT["Meter"] / 100.0,
    "dm": OpenLayers.INCHES_PER_UNIT["Meter"] * 100.0,
    "km": OpenLayers.INCHES_PER_UNIT["Meter"] * 1000.0,
    "kmi": OpenLayers.INCHES_PER_UNIT["nmi"],    //International Nautical Mile
    "fath": OpenLayers.INCHES_PER_UNIT["Fathom"], //International Fathom
    "ch": OpenLayers.INCHES_PER_UNIT["IntnlChain"],  //International Chain
    "link": OpenLayers.INCHES_PER_UNIT["IntnlLink"], //International Link
    "us-in": OpenLayers.INCHES_PER_UNIT["inches"], //U.S. Surveyor's Inch
    "us-ft": OpenLayers.INCHES_PER_UNIT["Foot"], //U.S. Surveyor's Foot
    "us-yd": OpenLayers.INCHES_PER_UNIT["Yard"], //U.S. Surveyor's Yard
    "us-ch": OpenLayers.INCHES_PER_UNIT["GunterChain"], //U.S. Surveyor's Chain
    "us-mi": OpenLayers.INCHES_PER_UNIT["Mile"],   //U.S. Surveyor's Statute Mile
    "ind-yd": OpenLayers.INCHES_PER_UNIT["IndianYd37"],  //Indian Yard
    "ind-ft": OpenLayers.INCHES_PER_UNIT["IndianFt37"],  //Indian Foot
    "ind-ch": 20.11669506 / OpenLayers.METERS_PER_INCH  //Indian Chain
});

/** 
 * Constant: DOTS_PER_INCH
 * {Integer} 72 (A sensible default)
 */
OpenLayers.DOTS_PER_INCH = 72;

/**
 * Function: normalizeScale
 * 
 * Parameters:
 * scale - {float}
 * 
 * Returns:
 * {Float} A normalized scale value, in 1 / X format. 
 *         This means that if a value less than one ( already 1/x) is passed
 *         in, it just returns scale directly. Otherwise, it returns 
 *         1 / scale
 */
OpenLayers.Util.normalizeScale = function (scale) {
    var normScale = (scale > 1.0) ? (1.0 / scale) 
                                  : scale;
    return normScale;
};

/**
 * Function: getResolutionFromScale
 * 
 * Parameters:
 * scale - {Float}
 * units - {String} Index into OpenLayers.INCHES_PER_UNIT hashtable.
 *                  Default is degrees
 * 
 * Returns:
 * {Float} The corresponding resolution given passed-in scale and unit 
 *     parameters.  If the given scale is falsey, the returned resolution will
 *     be undefined.
 */
OpenLayers.Util.getResolutionFromScale = function (scale, units) {
    var resolution;
    if (scale) {
        if (units == null) {
            units = "degrees";
        }
        var normScale = OpenLayers.Util.normalizeScale(scale);
        resolution = 1 / (normScale * OpenLayers.INCHES_PER_UNIT[units]
                                        * OpenLayers.DOTS_PER_INCH);        
    }
    return resolution;
};

/**
 * Function: getScaleFromResolution
 * 
 * Parameters:
 * resolution - {Float}
 * units - {String} Index into OpenLayers.INCHES_PER_UNIT hashtable.
 *                  Default is degrees
 * 
 * Returns:
 * {Float} The corresponding scale given passed-in resolution and unit 
 *         parameters.
 */
OpenLayers.Util.getScaleFromResolution = function (resolution, units) {

    if (units == null) {
        units = "degrees";
    }

    var scale = resolution * OpenLayers.INCHES_PER_UNIT[units] *
                    OpenLayers.DOTS_PER_INCH;
    return scale;
};

/**
 * Function: pagePosition
 * Calculates the position of an element on the page (see
 * http://code.google.com/p/doctype/wiki/ArticlePageOffset)
 *
 * OpenLayers.Util.pagePosition is based on Yahoo's getXY method, which is
 * Copyright (c) 2006, Yahoo! Inc.
 * All rights reserved.
 * 
 * Redistribution and use of this software in source and binary forms, with or
 * without modification, are permitted provided that the following conditions
 * are met:
 * 
 * * Redistributions of source code must retain the above copyright notice,
 *   this list of conditions and the following disclaimer.
 * 
 * * Redistributions in binary form must reproduce the above copyright notice,
 *   this list of conditions and the following disclaimer in the documentation
 *   and/or other materials provided with the distribution.
 * 
 * * Neither the name of Yahoo! Inc. nor the names of its contributors may be
 *   used to endorse or promote products derived from this software without
 *   specific prior written permission of Yahoo! Inc.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 
 * POSSIBILITY OF SUCH DAMAGE.
 *
 * Parameters:
 * forElement - {DOMElement}
 * 
 * Returns:
 * {Array} two item array, Left value then Top value.
 */
OpenLayers.Util.pagePosition =  function(forElement) {
    // NOTE: If element is hidden (display none or disconnected or any the
    // ancestors are hidden) we get (0,0) by default but we still do the
    // accumulation of scroll position.

    var pos = [0, 0];
    var viewportElement = OpenLayers.Util.getViewportElement();
    if (!forElement || forElement == window || forElement == viewportElement) {
        // viewport is always at 0,0 as that defined the coordinate system for
        // this function - this avoids special case checks in the code below
        return pos;
    }

    // Gecko browsers normally use getBoxObjectFor to calculate the position.
    // When invoked for an element with an implicit absolute position though it
    // can be off by one. Therefore the recursive implementation is used in
    // those (relatively rare) cases.
    var BUGGY_GECKO_BOX_OBJECT =
        OpenLayers.IS_GECKO && document.getBoxObjectFor &&
        OpenLayers.Element.getStyle(forElement, 'position') == 'absolute' &&
        (forElement.style.top == '' || forElement.style.left == '');

    var parent = null;
    var box;

    if (forElement.getBoundingClientRect) { // IE
        box = forElement.getBoundingClientRect();
        var scrollTop = window.pageYOffset || viewportElement.scrollTop;
        var scrollLeft = window.pageXOffset || viewportElement.scrollLeft;
        
        pos[0] = box.left + scrollLeft;
        pos[1] = box.top + scrollTop;

    } else if (document.getBoxObjectFor && !BUGGY_GECKO_BOX_OBJECT) { // gecko
        // Gecko ignores the scroll values for ancestors, up to 1.9.  See:
        // https://bugzilla.mozilla.org/show_bug.cgi?id=328881 and
        // https://bugzilla.mozilla.org/show_bug.cgi?id=330619

        box = document.getBoxObjectFor(forElement);
        var vpBox = document.getBoxObjectFor(viewportElement);
        pos[0] = box.screenX - vpBox.screenX;
        pos[1] = box.screenY - vpBox.screenY;

    } else { // safari/opera
        pos[0] = forElement.offsetLeft;
        pos[1] = forElement.offsetTop;
        parent = forElement.offsetParent;
        if (parent != forElement) {
            while (parent) {
                pos[0] += parent.offsetLeft;
                pos[1] += parent.offsetTop;
                parent = parent.offsetParent;
            }
        }

        var browser = OpenLayers.BROWSER_NAME;

        // opera & (safari absolute) incorrectly account for body offsetTop
        if (browser == "opera" || (browser == "safari" &&
              OpenLayers.Element.getStyle(forElement, 'position') == 'absolute')) {
            pos[1] -= document.body.offsetTop;
        }

        // accumulate the scroll positions for everything but the body element
        parent = forElement.offsetParent;
        while (parent && parent != document.body) {
            pos[0] -= parent.scrollLeft;
            // see https://bugs.opera.com/show_bug.cgi?id=249965
            if (browser != "opera" || parent.tagName != 'TR') {
                pos[1] -= parent.scrollTop;
            }
            parent = parent.offsetParent;
        }
    }
    
    return pos;
};

/**
 * Function: getViewportElement
 * Returns die viewport element of the document. The viewport element is
 * usually document.documentElement, except in IE,where it is either
 * document.body or document.documentElement, depending on the document's
 * compatibility mode (see
 * http://code.google.com/p/doctype/wiki/ArticleClientViewportElement)
 *
 * Returns:
 * {DOMElement}
 */
OpenLayers.Util.getViewportElement = function() {
    var viewportElement = arguments.callee.viewportElement;
    if (viewportElement == undefined) {
        viewportElement = (OpenLayers.BROWSER_NAME == "msie" &&
            document.compatMode != 'CSS1Compat') ? document.body :
            document.documentElement;
        arguments.callee.viewportElement = viewportElement;
    }
    return viewportElement;
};

/** 
 * Function: isEquivalentUrl
 * Test two URLs for equivalence. 
 * 
 * Setting 'ignoreCase' allows for case-independent comparison.
 * 
 * Comparison is based on: 
 *  - Protocol
 *  - Host (evaluated without the port)
 *  - Port (set 'ignorePort80' to ignore "80" values)
 *  - Hash ( set 'ignoreHash' to disable)
 *  - Pathname (for relative <-> absolute comparison) 
 *  - Arguments (so they can be out of order)
 *  
 * Parameters:
 * url1 - {String}
 * url2 - {String}
 * options - {Object} Allows for customization of comparison:
 *                    'ignoreCase' - Default is True
 *                    'ignorePort80' - Default is True
 *                    'ignoreHash' - Default is True
 *
 * Returns:
 * {Boolean} Whether or not the two URLs are equivalent
 */
OpenLayers.Util.isEquivalentUrl = function(url1, url2, options) {
    options = options || {};

    OpenLayers.Util.applyDefaults(options, {
        ignoreCase: true,
        ignorePort80: true,
        ignoreHash: true,
        splitArgs: false
    });

    var urlObj1 = OpenLayers.Util.createUrlObject(url1, options);
    var urlObj2 = OpenLayers.Util.createUrlObject(url2, options);

    //compare all keys except for "args" (treated below)
    for(var key in urlObj1) {
        if(key !== "args") {
            if(urlObj1[key] != urlObj2[key]) {
                return false;
            }
        }
    }

    // compare search args - irrespective of order
    for(var key in urlObj1.args) {
        if(urlObj1.args[key] != urlObj2.args[key]) {
            return false;
        }
        delete urlObj2.args[key];
    }
    // urlObj2 shouldn't have any args left
    for(var key in urlObj2.args) {
        return false;
    }
    
    return true;
};

/**
 * Function: createUrlObject
 * 
 * Parameters:
 * url - {String}
 * options - {Object} A hash of options.
 *
 * Valid options:
 *   ignoreCase - {Boolean} lowercase url,
 *   ignorePort80 - {Boolean} don't include explicit port if port is 80,
 *   ignoreHash - {Boolean} Don't include part of url after the hash (#).
 *   splitArgs - {Boolean} Split comma delimited params into arrays? Default is
 *       true.
 * 
 * Returns:
 * {Object} An object with separate url, a, port, host, and args parsed out 
 *          and ready for comparison
 */
OpenLayers.Util.createUrlObject = function(url, options) {
    options = options || {};

    // deal with relative urls first
    if(!(/^\w+:\/\//).test(url)) {
        var loc = window.location;
        var port = loc.port ? ":" + loc.port : "";
        var fullUrl = loc.protocol + "//" + loc.host.split(":").shift() + port;
        if(url.indexOf("/") === 0) {
            // full pathname
            url = fullUrl + url;
        } else {
            // relative to current path
            var parts = loc.pathname.split("/");
            parts.pop();
            url = fullUrl + parts.join("/") + "/" + url;
        }
    }
  
    if (options.ignoreCase) {
        url = url.toLowerCase(); 
    }

    var a = document.createElement('a');
    a.href = url;
    
    var urlObject = {};
    
    //host (without port)
    urlObject.host = a.host.split(":").shift();

    //protocol
    urlObject.protocol = a.protocol;  

    //port (get uniform browser behavior with port 80 here)
    if(options.ignorePort80) {
        urlObject.port = (a.port == "80" || a.port == "0") ? "" : a.port;
    } else {
        urlObject.port = (a.port == "" || a.port == "0") ? "80" : a.port;
    }

    //hash
    urlObject.hash = (options.ignoreHash || a.hash === "#") ? "" : a.hash;  
    
    //args
    var queryString = a.search;
    if (!queryString) {
        var qMark = url.indexOf("?");
        queryString = (qMark != -1) ? url.substr(qMark) : "";
    }
    urlObject.args = OpenLayers.Util.getParameters(queryString,
            {splitArgs: options.splitArgs});

    // pathname
    //
    // This is a workaround for Internet Explorer where
    // window.location.pathname has a leading "/", but
    // a.pathname has no leading "/".
    urlObject.pathname = (a.pathname.charAt(0) == "/") ? a.pathname : "/" + a.pathname;
    
    return urlObject; 
};
 
/**
 * Function: removeTail
 * Takes a url and removes everything after the ? and #
 * 
 * Parameters:
 * url - {String} The url to process
 * 
 * Returns:
 * {String} The string with all queryString and Hash removed
 */
OpenLayers.Util.removeTail = function(url) {
    var head = null;
    
    var qMark = url.indexOf("?");
    var hashMark = url.indexOf("#");

    if (qMark == -1) {
        head = (hashMark != -1) ? url.substr(0,hashMark) : url;
    } else {
        head = (hashMark != -1) ? url.substr(0,Math.min(qMark, hashMark)) 
                                  : url.substr(0, qMark);
    }
    return head;
};

/**
 * Constant: IS_GECKO
 * {Boolean} True if the userAgent reports the browser to use the Gecko engine
 */
OpenLayers.IS_GECKO = (function() {
    var ua = navigator.userAgent.toLowerCase();
    return ua.indexOf("webkit") == -1 && ua.indexOf("gecko") != -1;
})();

/**
 * Constant: CANVAS_SUPPORTED
 * {Boolean} True if canvas 2d is supported.
 */
OpenLayers.CANVAS_SUPPORTED = (function() {
    var elem = document.createElement('canvas');
    return !!(elem.getContext && elem.getContext('2d'));
})();

/**
 * Constant: BROWSER_NAME
 * {String}
 * A substring of the navigator.userAgent property.  Depending on the userAgent
 *     property, this will be the empty string or one of the following:
 *     * "opera" -- Opera
 *     * "msie"  -- Internet Explorer
 *     * "safari" -- Safari
 *     * "firefox" -- Firefox
 *     * "mozilla" -- Mozilla
 */
OpenLayers.BROWSER_NAME = (function() {
    var name = "";
    var ua = navigator.userAgent.toLowerCase();
    if (ua.indexOf("opera") != -1) {
        name = "opera";
    } else if (ua.indexOf("msie") != -1) {
        name = "msie";
    } else if (ua.indexOf("safari") != -1) {
        name = "safari";
    } else if (ua.indexOf("mozilla") != -1) {
        if (ua.indexOf("firefox") != -1) {
            name = "firefox";
        } else {
            name = "mozilla";
        }
    }
    return name;
})();

/**
 * Function: getBrowserName
 * 
 * Returns:
 * {String} A string which specifies which is the current 
 *          browser in which we are running. 
 * 
 *          Currently-supported browser detection and codes:
 *           * 'opera' -- Opera
 *           * 'msie'  -- Internet Explorer
 *           * 'safari' -- Safari
 *           * 'firefox' -- Firefox
 *           * 'mozilla' -- Mozilla
 * 
 *          If we are unable to property identify the browser, we 
 *           return an empty string.
 */
OpenLayers.Util.getBrowserName = function() {
    return OpenLayers.BROWSER_NAME;
};

/**
 * Method: getRenderedDimensions
 * Renders the contentHTML offscreen to determine actual dimensions for
 *     popup sizing. As we need layout to determine dimensions the content
 *     is rendered -9999px to the left and absolute to ensure the 
 *     scrollbars do not flicker
 *     
 * Parameters:
 * contentHTML
 * size - {<OpenLayers.Size>} If either the 'w' or 'h' properties is 
 *     specified, we fix that dimension of the div to be measured. This is 
 *     useful in the case where we have a limit in one dimension and must 
 *     therefore meaure the flow in the other dimension.
 * options - {Object}
 *
 * Allowed Options:
 *     displayClass - {String} Optional parameter.  A CSS class name(s) string
 *         to provide the CSS context of the rendered content.
 *     containerElement - {DOMElement} Optional parameter. Insert the HTML to 
 *         this node instead of the body root when calculating dimensions. 
 * 
 * Returns:
 * {<OpenLayers.Size>}
 */
OpenLayers.Util.getRenderedDimensions = function(contentHTML, size, options) {
    
    var w, h;
    
    // create temp container div with restricted size
    var container = document.createElement("div");
    container.style.visibility = "hidden";
        
    var containerElement = (options && options.containerElement) 
        ? options.containerElement : document.body;
    
    // Opera and IE7 can't handle a node with position:aboslute if it inherits
    // position:absolute from a parent.
    var parentHasPositionAbsolute = false;
    var superContainer = null;
    var parent = containerElement;
    while (parent && parent.tagName.toLowerCase()!="body") {
        var parentPosition = OpenLayers.Element.getStyle(parent, "position");
        if(parentPosition == "absolute") {
            parentHasPositionAbsolute = true;
            break;
        } else if (parentPosition && parentPosition != "static") {
            break;
        }
        parent = parent.parentNode;
    }
    if(parentHasPositionAbsolute && (containerElement.clientHeight === 0 || 
                                     containerElement.clientWidth === 0) ){
        superContainer = document.createElement("div");
        superContainer.style.visibility = "hidden";
        superContainer.style.position = "absolute";
        superContainer.style.overflow = "visible";
        superContainer.style.width = document.body.clientWidth + "px";
        superContainer.style.height = document.body.clientHeight + "px";
        superContainer.appendChild(container);
    }
    container.style.position = "absolute";

    //fix a dimension, if specified.
    if (size) {
        if (size.w) {
            w = size.w;
            container.style.width = w + "px";
        } else if (size.h) {
            h = size.h;
            container.style.height = h + "px";
        }
    }

    //add css classes, if specified
    if (options && options.displayClass) {
        container.className = options.displayClass;
    }
    
    // create temp content div and assign content
    var content = document.createElement("div");
    content.innerHTML = contentHTML;
    
    // we need overflow visible when calculating the size
    content.style.overflow = "visible";
    if (content.childNodes) {
        for (var i=0, l=content.childNodes.length; i<l; i++) {
            if (!content.childNodes[i].style) continue;
            content.childNodes[i].style.overflow = "visible";
        }
    }
    
    // add content to restricted container 
    container.appendChild(content);
    
    // append container to body for rendering
    if (superContainer) {
        containerElement.appendChild(superContainer);
    } else {
        containerElement.appendChild(container);
    }
    
    // calculate scroll width of content and add corners and shadow width
    if (!w) {
        w = parseInt(content.scrollWidth);
    
        // update container width to allow height to adjust
        container.style.width = w + "px";
    }        
    // capture height and add shadow and corner image widths
    if (!h) {
        h = parseInt(content.scrollHeight);
    }

    // remove elements
    container.removeChild(content);
    if (superContainer) {
        superContainer.removeChild(container);
        containerElement.removeChild(superContainer);
    } else {
        containerElement.removeChild(container);
    }
    
    return new OpenLayers.Size(w, h);
};

/**
 * APIFunction: getScrollbarWidth
 * This function has been modified by the OpenLayers from the original version,
 *     written by Matthew Eernisse and released under the Apache 2 
 *     license here:
 * 
 *     http://www.fleegix.org/articles/2006/05/30/getting-the-scrollbar-width-in-pixels
 * 
 *     It has been modified simply to cache its value, since it is physically 
 *     impossible that this code could ever run in more than one browser at 
 *     once. 
 * 
 * Returns:
 * {Integer}
 */
OpenLayers.Util.getScrollbarWidth = function() {
    
    var scrollbarWidth = OpenLayers.Util._scrollbarWidth;
    
    if (scrollbarWidth == null) {
        var scr = null;
        var inn = null;
        var wNoScroll = 0;
        var wScroll = 0;
    
        // Outer scrolling div
        scr = document.createElement('div');
        scr.style.position = 'absolute';
        scr.style.top = '-1000px';
        scr.style.left = '-1000px';
        scr.style.width = '100px';
        scr.style.height = '50px';
        // Start with no scrollbar
        scr.style.overflow = 'hidden';
    
        // Inner content div
        inn = document.createElement('div');
        inn.style.width = '100%';
        inn.style.height = '200px';
    
        // Put the inner div in the scrolling div
        scr.appendChild(inn);
        // Append the scrolling div to the doc
        document.body.appendChild(scr);
    
        // Width of the inner div sans scrollbar
        wNoScroll = inn.offsetWidth;
    
        // Add the scrollbar
        scr.style.overflow = 'scroll';
        // Width of the inner div width scrollbar
        wScroll = inn.offsetWidth;
    
        // Remove the scrolling div from the doc
        document.body.removeChild(document.body.lastChild);
    
        // Pixel width of the scroller
        OpenLayers.Util._scrollbarWidth = (wNoScroll - wScroll);
        scrollbarWidth = OpenLayers.Util._scrollbarWidth;
    }

    return scrollbarWidth;
};

/**
 * APIFunction: getFormattedLonLat
 * This function will return latitude or longitude value formatted as 
 *
 * Parameters:
 * coordinate - {Float} the coordinate value to be formatted
 * axis - {String} value of either 'lat' or 'lon' to indicate which axis is to
 *          to be formatted (default = lat)
 * dmsOption - {String} specify the precision of the output can be one of:
 *           'dms' show degrees minutes and seconds
 *           'dm' show only degrees and minutes
 *           'd' show only degrees
 * 
 * Returns:
 * {String} the coordinate value formatted as a string
 */
OpenLayers.Util.getFormattedLonLat = function(coordinate, axis, dmsOption) {
    if (!dmsOption) {
        dmsOption = 'dms';    //default to show degree, minutes, seconds
    }

    coordinate = (coordinate+540)%360 - 180; // normalize for sphere being round

    var abscoordinate = Math.abs(coordinate);
    var coordinatedegrees = Math.floor(abscoordinate);

    var coordinateminutes = (abscoordinate - coordinatedegrees)/(1/60);
    var tempcoordinateminutes = coordinateminutes;
    coordinateminutes = Math.floor(coordinateminutes);
    var coordinateseconds = (tempcoordinateminutes - coordinateminutes)/(1/60);
    coordinateseconds =  Math.round(coordinateseconds*10);
    coordinateseconds /= 10;

    if( coordinateseconds >= 60) { 
        coordinateseconds -= 60; 
        coordinateminutes += 1; 
        if( coordinateminutes >= 60) { 
            coordinateminutes -= 60; 
            coordinatedegrees += 1; 
        } 
    }
    
    if( coordinatedegrees < 10 ) {
        coordinatedegrees = "0" + coordinatedegrees;
    }
    var str = coordinatedegrees + "\u00B0";

    if (dmsOption.indexOf('dm') >= 0) {
        if( coordinateminutes < 10 ) {
            coordinateminutes = "0" + coordinateminutes;
        }
        str += coordinateminutes + "'";
  
        if (dmsOption.indexOf('dms') >= 0) {
            if( coordinateseconds < 10 ) {
                coordinateseconds = "0" + coordinateseconds;
            }
            str += coordinateseconds + '"';
        }
    }
    
    if (axis == "lon") {
        str += coordinate < 0 ? OpenLayers.i18n("W") : OpenLayers.i18n("E");
    } else {
        str += coordinate < 0 ? OpenLayers.i18n("S") : OpenLayers.i18n("N");
    }
    return str;
};

/* ======================================================================
    OpenLayers/Util/vendorPrefix.js
   ====================================================================== */

/* Copyright (c) 2006-2013 by OpenLayers Contributors (see authors.txt for
 * full list of contributors). Published under the 2-clause BSD license.
 * See license.txt in the OpenLayers distribution or repository for the
 * full text of the license. */

/**
 * @requires OpenLayers/SingleFile.js
 */

OpenLayers.Util = OpenLayers.Util || {};
/**
 * Namespace: OpenLayers.Util.vendorPrefix
 * A collection of utility functions to detect vendor prefixed features
 */
OpenLayers.Util.vendorPrefix = (function() {
    "use strict";
    
    var VENDOR_PREFIXES = ["", "O", "ms", "Moz", "Webkit"],
        divStyle = document.createElement("div").style,
        cssCache = {},
        jsCache = {};

    
    /**
     * Function: domToCss
     * Converts a upper camel case DOM style property name to a CSS property
     *      i.e. transformOrigin -> transform-origin
     *      or   WebkitTransformOrigin -> -webkit-transform-origin
     *
     * Parameters:
     * prefixedDom - {String} The property to convert
     *
     * Returns:
     * {String} The CSS property
     */
    function domToCss(prefixedDom) {
        if (!prefixedDom) { return null; }
        return prefixedDom.
            replace(/([A-Z])/g, function(c) { return "-" + c.toLowerCase(); }).
            replace(/^ms-/, "-ms-");
    }

    /**
     * APIMethod: css
     * Detect which property is used for a CSS property
     *
     * Parameters:
     * property - {String} The standard (unprefixed) CSS property name
     *
     * Returns:
     * {String} The standard CSS property, prefixed property or null if not
     *          supported
     */
    function css(property) {
        if (cssCache[property] === undefined) {
            var domProperty = property.
                replace(/(-[\s\S])/g, function(c) { return c.charAt(1).toUpperCase(); });
            var prefixedDom = style(domProperty);
            cssCache[property] = domToCss(prefixedDom);
        }
        return cssCache[property];
    }

    /**
     * APIMethod: js
     * Detect which property is used for a JS property/method
     *
     * Parameters:
     * obj - {Object} The object to test on
     * property - {String} The standard (unprefixed) JS property name
     *
     * Returns:
     * {String} The standard JS property, prefixed property or null if not
     *          supported
     */
    function js(obj, property) {
        if (jsCache[property] === undefined) {
            var tmpProp,
                i = 0,
                l = VENDOR_PREFIXES.length,
                prefix,
                isStyleObj = (typeof obj.cssText !== "undefined");

            jsCache[property] = null;
            for(; i<l; i++) {
                prefix = VENDOR_PREFIXES[i];
                if(prefix) {
                    if (!isStyleObj) {
                        // js prefix should be lower-case, while style
                        // properties have upper case on first character
                        prefix = prefix.toLowerCase();
                    }
                    tmpProp = prefix + property.charAt(0).toUpperCase() + property.slice(1);
                } else {
                    tmpProp = property;
                }

                if(obj[tmpProp] !== undefined) {
                    jsCache[property] = tmpProp;
                    break;
                }
            }
        }
        return jsCache[property];
    }
    
    /**
     * APIMethod: style
     * Detect which property is used for a DOM style property
     *
     * Parameters:
     * property - {String} The standard (unprefixed) style property name
     *
     * Returns:
     * {String} The standard style property, prefixed property or null if not
     *          supported
     */
    function style(property) {
        return js(divStyle, property);
    }
    
    return {
        css:      css,
        js:       js,
        style:    style,
        
        // used for testing
        cssCache:       cssCache,
        jsCache:        jsCache
    };
}());
/* ======================================================================
    OpenLayers/Events.js
   ====================================================================== */

/* Copyright (c) 2006-2013 by OpenLayers Contributors (see authors.txt for
 * full list of contributors). Published under the 2-clause BSD license.
 * See license.txt in the OpenLayers distribution or repository for the
 * full text of the license. */


/**
 * @requires OpenLayers/Util.js
 */

/**
 * Namespace: OpenLayers.Event
 * Utility functions for event handling.
 */
OpenLayers.Event = {

    /** 
     * Property: observers 
     * {Object} A hashtable cache of the event observers. Keyed by
     * element._eventCacheID 
     */
    observers: false,

    /**
     * Constant: KEY_SPACE
     * {int}
     */
    KEY_SPACE: 32,
    
    /** 
     * Constant: KEY_BACKSPACE 
     * {int} 
     */
    KEY_BACKSPACE: 8,

    /** 
     * Constant: KEY_TAB 
     * {int} 
     */
    KEY_TAB: 9,

    /** 
     * Constant: KEY_RETURN 
     * {int} 
     */
    KEY_RETURN: 13,

    /** 
     * Constant: KEY_ESC 
     * {int} 
     */
    KEY_ESC: 27,

    /** 
     * Constant: KEY_LEFT 
     * {int} 
     */
    KEY_LEFT: 37,

    /** 
     * Constant: KEY_UP 
     * {int} 
     */
    KEY_UP: 38,

    /** 
     * Constant: KEY_RIGHT 
     * {int} 
     */
    KEY_RIGHT: 39,

    /** 
     * Constant: KEY_DOWN 
     * {int} 
     */
    KEY_DOWN: 40,

    /** 
     * Constant: KEY_DELETE 
     * {int} 
     */
    KEY_DELETE: 46,


    /**
     * Method: element
     * Cross browser event element detection.
     * 
     * Parameters:
     * event - {Event} 
     * 
     * Returns:
     * {DOMElement} The element that caused the event 
     */
    element: function(event) {
        return event.target || event.srcElement;
    },

    /**
     * Method: isSingleTouch
     * Determine whether event was caused by a single touch
     *
     * Parameters:
     * event - {Event}
     *
     * Returns:
     * {Boolean}
     */
    isSingleTouch: function(event) {
        return event.touches && event.touches.length == 1;
    },

    /**
     * Method: isMultiTouch
     * Determine whether event was caused by a multi touch
     *
     * Parameters:
     * event - {Event}
     *
     * Returns:
     * {Boolean}
     */
    isMultiTouch: function(event) {
        return event.touches && event.touches.length > 1;
    },

    /**
     * Method: isLeftClick
     * Determine whether event was caused by a left click. 
     *
     * Parameters:
     * event - {Event} 
     * 
     * Returns:
     * {Boolean}
     */
    isLeftClick: function(event) {
        return (((event.which) && (event.which == 1)) ||
                ((event.button) && (event.button == 1)));
    },

    /**
     * Method: isRightClick
     * Determine whether event was caused by a right mouse click. 
     *
     * Parameters:
     * event - {Event} 
     * 
     * Returns:
     * {Boolean}
     */
     isRightClick: function(event) {
        return (((event.which) && (event.which == 3)) ||
                ((event.button) && (event.button == 2)));
    },
     
    /**
     * Method: stop
     * Stops an event from propagating. 
     *
     * Parameters: 
     * event - {Event} 
     * allowDefault - {Boolean} If true, we stop the event chain but 
     *     still allow the default browser behaviour (text selection,
     *     radio-button clicking, etc).  Default is false.
     */
    stop: function(event, allowDefault) {
        
        if (!allowDefault) { 
            OpenLayers.Event.preventDefault(event);
        }
                
        if (event.stopPropagation) {
            event.stopPropagation();
        } else {
            event.cancelBubble = true;
        }
    },

    /**
     * Method: preventDefault
     * Cancels the event if it is cancelable, without stopping further
     * propagation of the event.
     *
     * Parameters:
     * event - {Event}
     */
    preventDefault: function(event) {
        if (event.preventDefault) {
            event.preventDefault();
        } else {
            event.returnValue = false;
        }
    },

    /** 
     * Method: findElement
     * 
     * Parameters:
     * event - {Event} 
     * tagName - {String} 
     * 
     * Returns:
     * {DOMElement} The first node with the given tagName, starting from the
     * node the event was triggered on and traversing the DOM upwards
     */
    findElement: function(event, tagName) {
        var element = OpenLayers.Event.element(event);
        while (element.parentNode && (!element.tagName ||
              (element.tagName.toUpperCase() != tagName.toUpperCase()))){
            element = element.parentNode;
        }
        return element;
    },

    /** 
     * Method: observe
     * 
     * Parameters:
     * elementParam - {DOMElement || String} 
     * name - {String} 
     * observer - {function} 
     * useCapture - {Boolean} 
     */
    observe: function(elementParam, name, observer, useCapture) {
        var element = OpenLayers.Util.getElement(elementParam);
        useCapture = useCapture || false;

        if (name == 'keypress' &&
           (navigator.appVersion.match(/Konqueror|Safari|KHTML/)
           || element.attachEvent)) {
            name = 'keydown';
        }

        //if observers cache has not yet been created, create it
        if (!this.observers) {
            this.observers = {};
        }

        //if not already assigned, make a new unique cache ID
        if (!element._eventCacheID) {
            var idPrefix = "eventCacheID_";
            if (element.id) {
                idPrefix = element.id + "_" + idPrefix;
            }
            element._eventCacheID = OpenLayers.Util.createUniqueID(idPrefix);
        }

        var cacheID = element._eventCacheID;

        //if there is not yet a hash entry for this element, add one
        if (!this.observers[cacheID]) {
            this.observers[cacheID] = [];
        }

        //add a new observer to this element's list
        this.observers[cacheID].push({
            'element': element,
            'name': name,
            'observer': observer,
            'useCapture': useCapture
        });

        //add the actual browser event listener
        if (element.addEventListener) {
            element.addEventListener(name, observer, useCapture);
        } else if (element.attachEvent) {
            element.attachEvent('on' + name, observer);
        }
    },

    /** 
     * Method: stopObservingElement
     * Given the id of an element to stop observing, cycle through the 
     *   element's cached observers, calling stopObserving on each one, 
     *   skipping those entries which can no longer be removed.
     * 
     * parameters:
     * elementParam - {DOMElement || String} 
     */
    stopObservingElement: function(elementParam) {
        var element = OpenLayers.Util.getElement(elementParam);
        var cacheID = element._eventCacheID;

        this._removeElementObservers(OpenLayers.Event.observers[cacheID]);
    },

    /**
     * Method: _removeElementObservers
     *
     * Parameters:
     * elementObservers - {Array(Object)} Array of (element, name, 
     *                                         observer, usecapture) objects, 
     *                                         taken directly from hashtable
     */
    _removeElementObservers: function(elementObservers) {
        if (elementObservers) {
            for(var i = elementObservers.length-1; i >= 0; i--) {
                var entry = elementObservers[i];
                OpenLayers.Event.stopObserving.apply(this, [
                    entry.element, entry.name, entry.observer, entry.useCapture
                ]);
            }
        }
    },

    /**
     * Method: stopObserving
     * 
     * Parameters:
     * elementParam - {DOMElement || String} 
     * name - {String} 
     * observer - {function} 
     * useCapture - {Boolean} 
     *  
     * Returns:
     * {Boolean} Whether or not the event observer was removed
     */
    stopObserving: function(elementParam, name, observer, useCapture) {
        useCapture = useCapture || false;
    
        var element = OpenLayers.Util.getElement(elementParam);
        var cacheID = element._eventCacheID;

        if (name == 'keypress') {
            if ( navigator.appVersion.match(/Konqueror|Safari|KHTML/) || 
                 element.detachEvent) {
              name = 'keydown';
            }
        }

        // find element's entry in this.observers cache and remove it
        var foundEntry = false;
        var elementObservers = OpenLayers.Event.observers[cacheID];
        if (elementObservers) {
    
            // find the specific event type in the element's list
            var i=0;
            while(!foundEntry && i < elementObservers.length) {
                var cacheEntry = elementObservers[i];
    
                if ((cacheEntry.name == name) &&
                    (cacheEntry.observer == observer) &&
                    (cacheEntry.useCapture == useCapture)) {
    
                    elementObservers.splice(i, 1);
                    if (elementObservers.length == 0) {
                        delete OpenLayers.Event.observers[cacheID];
                    }
                    foundEntry = true;
                    break; 
                }
                i++;           
            }
        }
    
        //actually remove the event listener from browser
        if (foundEntry) {
            if (element.removeEventListener) {
                element.removeEventListener(name, observer, useCapture);
            } else if (element && element.detachEvent) {
                element.detachEvent('on' + name, observer);
            }
        }
        return foundEntry;
    },
    
    /** 
     * Method: unloadCache
     * Cycle through all the element entries in the events cache and call
     *   stopObservingElement on each. 
     */
    unloadCache: function() {
        // check for OpenLayers.Event before checking for observers, because
        // OpenLayers.Event may be undefined in IE if no map instance was
        // created
        if (OpenLayers.Event && OpenLayers.Event.observers) {
            for (var cacheID in OpenLayers.Event.observers) {
                var elementObservers = OpenLayers.Event.observers[cacheID];
                OpenLayers.Event._removeElementObservers.apply(this, 
                                                           [elementObservers]);
            }
            OpenLayers.Event.observers = false;
        }
    },

    CLASS_NAME: "OpenLayers.Event"
};

/* prevent memory leaks in IE */
OpenLayers.Event.observe(window, 'unload', OpenLayers.Event.unloadCache, false);

/**
 * Class: OpenLayers.Events
 */
OpenLayers.Events = OpenLayers.Class({

    /** 
     * Constant: BROWSER_EVENTS
     * {Array(String)} supported events 
     */
    BROWSER_EVENTS: [
        "mouseover", "mouseout",
        "mousedown", "mouseup", "mousemove", 
        "click", "dblclick", "rightclick", "dblrightclick",
        "resize", "focus", "blur",
        "touchstart", "touchmove", "touchend",
        "keydown"
    ],

    /** 
     * Property: listeners 
     * {Object} Hashtable of Array(Function): events listener functions  
     */
    listeners: null,

    /** 
     * Property: object 
     * {Object}  the code object issuing application events 
     */
    object: null,

    /** 
     * Property: element 
     * {DOMElement}  the DOM element receiving browser events 
     */
    element: null,

    /** 
     * Property: eventHandler 
     * {Function}  bound event handler attached to elements 
     */
    eventHandler: null,

    /** 
     * APIProperty: fallThrough 
     * {Boolean} 
     */
    fallThrough: null,

    /** 
     * APIProperty: includeXY
     * {Boolean} Should the .xy property automatically be created for browser
     *    mouse events? In general, this should be false. If it is true, then
     *    mouse events will automatically generate a '.xy' property on the 
     *    event object that is passed. (Prior to OpenLayers 2.7, this was true
     *    by default.) Otherwise, you can call the getMousePosition on the
     *    relevant events handler on the object available via the 'evt.object'
     *    property of the evt object. So, for most events, you can call:
     *    function named(evt) { 
     *        this.xy = this.object.events.getMousePosition(evt) 
     *    } 
     *
     *    This option typically defaults to false for performance reasons:
     *    when creating an events object whose primary purpose is to manage
     *    relatively positioned mouse events within a div, it may make
     *    sense to set it to true.
     *
     *    This option is also used to control whether the events object caches
     *    offsets. If this is false, it will not: the reason for this is that
     *    it is only expected to be called many times if the includeXY property
     *    is set to true. If you set this to true, you are expected to clear 
     *    the offset cache manually (using this.clearMouseCache()) if:
     *        the border of the element changes
     *        the location of the element in the page changes
    */
    includeXY: false,      
    
    /**
     * APIProperty: extensions
     * {Object} Event extensions registered with this instance. Keys are
     *     event types, values are {OpenLayers.Events.*} extension instances or
     *     {Boolean} for events that an instantiated extension provides in
     *     addition to the one it was created for.
     *
     * Extensions create an event in addition to browser events, which usually
     * fires when a sequence of browser events is completed. Extensions are
     * automatically instantiated when a listener is registered for an event
     * provided by an extension.
     *
     * Extensions are created in the <OpenLayers.Events> namespace using
     * <OpenLayers.Class>, and named after the event they provide.
     * The constructor receives the target <OpenLayers.Events> instance as
     * argument. Extensions that need to capture browser events before they
     * propagate can register their listeners events using <register>, with
     * {extension: true} as 4th argument.
     *
     * If an extension creates more than one event, an alias for each event
     * type should be created and reference the same class. The constructor
     * should set a reference in the target's extensions registry to itself.
     *
     * Below is a minimal extension that provides the "foostart" and "fooend"
     * event types, which replace the native "click" event type if clicked on
     * an element with the css class "foo":
     *
     * (code)
     *   OpenLayers.Events.foostart = OpenLayers.Class({
     *       initialize: function(target) {
     *           this.target = target;
     *           this.target.register("click", this, this.doStuff, {extension: true});
     *           // only required if extension provides more than one event type
     *           this.target.extensions["foostart"] = true;
     *           this.target.extensions["fooend"] = true;
     *       },
     *       destroy: function() {
     *           var target = this.target;
     *           target.unregister("click", this, this.doStuff);
     *           delete this.target;
     *           // only required if extension provides more than one event type
     *           delete target.extensions["foostart"];
     *           delete target.extensions["fooend"];
     *       },
     *       doStuff: function(evt) {
     *           var propagate = true;
     *           if (OpenLayers.Event.element(evt).className === "foo") {
     *               propagate = false;
     *               var target = this.target;
     *               target.triggerEvent("foostart");
     *               window.setTimeout(function() {
     *                   target.triggerEvent("fooend");
     *               }, 1000);
     *           }
     *           return propagate;
     *       }
     *   });
     *   // only required if extension provides more than one event type
     *   OpenLayers.Events.fooend = OpenLayers.Events.foostart;
     * (end)
     * 
     */
    extensions: null,
    
    /**
     * Property: extensionCount
     * {Object} Keys are event types (like in <listeners>), values are the
     *     number of extension listeners for each event type.
     */
    extensionCount: null,

    /**
     * Method: clearMouseListener
     * A version of <clearMouseCache> that is bound to this instance so that
     *     it can be used with <OpenLayers.Event.observe> and
     *     <OpenLayers.Event.stopObserving>.
     */
    clearMouseListener: null,

    /**
     * Constructor: OpenLayers.Events
     * Construct an OpenLayers.Events object.
     *
     * Parameters:
     * object - {Object} The js object to which this Events object  is being added
     * element - {DOMElement} A dom element to respond to browser events
     * eventTypes - {Array(String)} Deprecated.  Array of custom application
     *     events.  A listener may be registered for any named event, regardless
     *     of the values provided here.
     * fallThrough - {Boolean} Allow events to fall through after these have
     *                         been handled?
     * options - {Object} Options for the events object.
     */
    initialize: function (object, element, eventTypes, fallThrough, options) {
        OpenLayers.Util.extend(this, options);
        this.object     = object;
        this.fallThrough = fallThrough;
        this.listeners  = {};
        this.extensions = {};
        this.extensionCount = {};
        this._msTouches = [];
        
        // if a dom element is specified, add a listeners list 
        // for browser events on the element and register them
        if (element != null) {
            this.attachToElement(element);
        }
    },

    /**
     * APIMethod: destroy
     */
    destroy: function () {
        for (var e in this.extensions) {
            if (typeof this.extensions[e] !== "boolean") {
                this.extensions[e].destroy();
            }
        }
        this.extensions = null;
        if (this.element) {
            OpenLayers.Event.stopObservingElement(this.element);
            if(this.element.hasScrollEvent) {
                OpenLayers.Event.stopObserving(
                    window, "scroll", this.clearMouseListener
                );
            }
        }
        this.element = null;

        this.listeners = null;
        this.object = null;
        this.fallThrough = null;
        this.eventHandler = null;
    },

    /**
     * APIMethod: addEventType
     * Deprecated.  Any event can be triggered without adding it first.
     * 
     * Parameters:
     * eventName - {String}
     */
    addEventType: function(eventName) {
    },

    /**
     * Method: attachToElement
     *
     * Parameters:
     * element - {HTMLDOMElement} a DOM element to attach browser events to
     */
    attachToElement: function (element) {
        if (this.element) {
            OpenLayers.Event.stopObservingElement(this.element);
        } else {
            // keep a bound copy of handleBrowserEvent() so that we can
            // pass the same function to both Event.observe() and .stopObserving()
            this.eventHandler = OpenLayers.Function.bindAsEventListener(
                this.handleBrowserEvent, this
            );
            
            // to be used with observe and stopObserving
            this.clearMouseListener = OpenLayers.Function.bind(
                this.clearMouseCache, this
            );
        }
        this.element = element;
        var msTouch = !!window.navigator.msMaxTouchPoints;
        var type;
        for (var i = 0, len = this.BROWSER_EVENTS.length; i < len; i++) {
            type = this.BROWSER_EVENTS[i];
            // register the event cross-browser
            OpenLayers.Event.observe(element, type, this.eventHandler
            );
            if (msTouch && type.indexOf('touch') === 0) {
                this.addMsTouchListener(element, type, this.eventHandler);
            }
        }
        // disable dragstart in IE so that mousedown/move/up works normally
        OpenLayers.Event.observe(element, "dragstart", OpenLayers.Event.stop);
    },
    
    /**
     * APIMethod: on
     * Convenience method for registering listeners with a common scope.
     *     Internally, this method calls <register> as shown in the examples
     *     below.
     *
     * Example use:
     * (code)
     * // register a single listener for the "loadstart" event
     * events.on({"loadstart": loadStartListener});
     *
     * // this is equivalent to the following
     * events.register("loadstart", undefined, loadStartListener);
     *
     * // register multiple listeners to be called with the same `this` object
     * events.on({
     *     "loadstart": loadStartListener,
     *     "loadend": loadEndListener,
     *     scope: object
     * });
     *
     * // this is equivalent to the following
     * events.register("loadstart", object, loadStartListener);
     * events.register("loadend", object, loadEndListener);
     * (end)
     *
     * Parameters:
     *  object - {Object}     
     */
    on: function(object) {
        for(var type in object) {
            if(type != "scope" && object.hasOwnProperty(type)) {
                this.register(type, object.scope, object[type]);
            }
        }
    },

    /**
     * APIMethod: register
     * Register an event on the events object.
     *
     * When the event is triggered, the 'func' function will be called, in the
     * context of 'obj'. Imagine we were to register an event, specifying an 
     * OpenLayers.Bounds Object as 'obj'. When the event is triggered, the 
     * context in the callback function will be our Bounds object. This means
     * that within our callback function, we can access the properties and 
     * methods of the Bounds object through the "this" variable. So our 
     * callback could execute something like: 
     * :    leftStr = "Left: " + this.left;
     *   
     *                   or
     *  
     * :    centerStr = "Center: " + this.getCenterLonLat();
     *
     * Parameters:
     * type - {String} Name of the event to register
     * obj - {Object} The object to bind the context to for the callback#.
     *     If no object is specified, default is the Events's 'object' property.
     * func - {Function} The callback function. If no callback is 
     *     specified, this function does nothing.
     * priority - {Boolean|Object} If true, adds the new listener to the
     *     *front* of the events queue instead of to the end.
     *
     * Valid options for priority:
     * extension - {Boolean} If true, then the event will be registered as
     *     extension event. Extension events are handled before all other
     *     events.
     */
    register: function (type, obj, func, priority) {
        if (type in OpenLayers.Events && !this.extensions[type]) {
            this.extensions[type] = new OpenLayers.Events[type](this);
        }
        if (func != null) {
            if (obj == null)  {
                obj = this.object;
            }
            var listeners = this.listeners[type];
            if (!listeners) {
                listeners = [];
                this.listeners[type] = listeners;
                this.extensionCount[type] = 0;
            }
            var listener = {obj: obj, func: func};
            if (priority) {
                listeners.splice(this.extensionCount[type], 0, listener);
                if (typeof priority === "object" && priority.extension) {
                    this.extensionCount[type]++;
                }
            } else {
                listeners.push(listener);
            }
        }
    },

    /**
     * APIMethod: registerPriority
     * Same as register() but adds the new listener to the *front* of the
     *     events queue instead of to the end.
     *    
     *     TODO: get rid of this in 3.0 - Decide whether listeners should be 
     *     called in the order they were registered or in reverse order.
     *
     *
     * Parameters:
     * type - {String} Name of the event to register
     * obj - {Object} The object to bind the context to for the callback#.
     *                If no object is specified, default is the Events's 
     *                'object' property.
     * func - {Function} The callback function. If no callback is 
     *                   specified, this function does nothing.
     */
    registerPriority: function (type, obj, func) {
        this.register(type, obj, func, true);
    },
    
    /**
     * APIMethod: un
     * Convenience method for unregistering listeners with a common scope.
     *     Internally, this method calls <unregister> as shown in the examples
     *     below.
     *
     * Example use:
     * (code)
     * // unregister a single listener for the "loadstart" event
     * events.un({"loadstart": loadStartListener});
     *
     * // this is equivalent to the following
     * events.unregister("loadstart", undefined, loadStartListener);
     *
     * // unregister multiple listeners with the same `this` object
     * events.un({
     *     "loadstart": loadStartListener,
     *     "loadend": loadEndListener,
     *     scope: object
     * });
     *
     * // this is equivalent to the following
     * events.unregister("loadstart", object, loadStartListener);
     * events.unregister("loadend", object, loadEndListener);
     * (end)
     */
    un: function(object) {
        for(var type in object) {
            if(type != "scope" && object.hasOwnProperty(type)) {
                this.unregister(type, object.scope, object[type]);
            }
        }
    },

    /**
     * APIMethod: unregister
     *
     * Parameters:
     * type - {String} 
     * obj - {Object} If none specified, defaults to this.object
     * func - {Function} 
     */
    unregister: function (type, obj, func) {
        if (obj == null)  {
            obj = this.object;
        }
        var listeners = this.listeners[type];
        if (listeners != null) {
            for (var i=0, len=listeners.length; i<len; i++) {
                if (listeners[i].obj == obj && listeners[i].func == func) {
                    listeners.splice(i, 1);
                    break;
                }
            }
        }
    },

    /** 
     * Method: remove
     * Remove all listeners for a given event type. If type is not registered,
     *     does nothing.
     *
     * Parameters:
     * type - {String} 
     */
    remove: function(type) {
        if (this.listeners[type] != null) {
            this.listeners[type] = [];
        }
    },

    /**
     * APIMethod: triggerEvent
     * Trigger a specified registered event.  
     * 
     * Parameters:
     * type - {String} 
     * evt - {Event || Object} will be passed to the listeners.
     *
     * Returns:
     * {Boolean} The last listener return.  If a listener returns false, the
     *     chain of listeners will stop getting called.
     */
    triggerEvent: function (type, evt) {
        var listeners = this.listeners[type];

        // fast path
        if(!listeners || listeners.length == 0) {
            return undefined;
        }

        // prep evt object with object & div references
        if (evt == null) {
            evt = {};
        }
        evt.object = this.object;
        evt.element = this.element;
        if(!evt.type) {
            evt.type = type;
        }
    
        // execute all callbacks registered for specified type
        // get a clone of the listeners array to
        // allow for splicing during callbacks
        listeners = listeners.slice();
        var continueChain;
        for (var i=0, len=listeners.length; i<len; i++) {
            var callback = listeners[i];
            // bind the context to callback.obj
            continueChain = callback.func.apply(callback.obj, [evt]);

            if ((continueChain != undefined) && (continueChain == false)) {
                // if callback returns false, execute no more callbacks.
                break;
            }
        }
        // don't fall through to other DOM elements
        if (!this.fallThrough) {           
            OpenLayers.Event.stop(evt, true);
        }
        return continueChain;
    },

    /**
     * Method: handleBrowserEvent
     * Basically just a wrapper to the triggerEvent() function, but takes 
     *     care to set a property 'xy' on the event with the current mouse 
     *     position.
     *
     * Parameters:
     * evt - {Event} 
     */
    handleBrowserEvent: function (evt) {
        var type = evt.type, listeners = this.listeners[type];
        if(!listeners || listeners.length == 0) {
            // noone's listening, bail out
            return;
        }
        // add clientX & clientY to all events - corresponds to average x, y
        var touches = evt.touches;
        if (touches && touches[0]) {
            var x = 0;
            var y = 0;
            var num = touches.length;
            var touch;
            for (var i=0; i<num; ++i) {
                touch = this.getTouchClientXY(touches[i]);
                x += touch.clientX;
                y += touch.clientY;
            }
            evt.clientX = x / num;
            evt.clientY = y / num;
        }
        if (this.includeXY) {
            evt.xy = this.getMousePosition(evt);
        } 
        this.triggerEvent(type, evt);
    },
    
    /**
     * Method: getTouchClientXY
     * WebKit has a few bugs for clientX/clientY. This method detects them
     * and calculate the correct values.
     *
     * Parameters:
     * evt - {Touch} a Touch object from a TouchEvent
     * 
     * Returns:
     * {Object} An object with only clientX and clientY properties with the
     * calculated values.
     */
    getTouchClientXY: function (evt) {
        // olMochWin is to override window, used for testing
        var win = window.olMockWin || window,
            winPageX = win.pageXOffset,
            winPageY = win.pageYOffset,
            x = evt.clientX,
            y = evt.clientY;
        
        if (evt.pageY === 0 && Math.floor(y) > Math.floor(evt.pageY) ||
            evt.pageX === 0 && Math.floor(x) > Math.floor(evt.pageX)) {
            // iOS4 include scroll offset in clientX/Y
            x = x - winPageX;
            y = y - winPageY;
        } else if (y < (evt.pageY - winPageY) || x < (evt.pageX - winPageX) ) {
            // Some Android browsers have totally bogus values for clientX/Y
            // when scrolling/zooming a page
            x = evt.pageX - winPageX;
            y = evt.pageY - winPageY;
        }
        
        evt.olClientX = x;
        evt.olClientY = y;
        
        return {
            clientX: x,
            clientY: y
        };
    },
    
    /**
     * APIMethod: clearMouseCache
     * Clear cached data about the mouse position. This should be called any 
     *     time the element that events are registered on changes position 
     *     within the page.
     */
    clearMouseCache: function() { 
        this.element.scrolls = null;
        this.element.lefttop = null;
        this.element.offsets = null;
    },      

    /**
     * Method: getMousePosition
     * 
     * Parameters:
     * evt - {Event} 
     * 
     * Returns:
     * {<OpenLayers.Pixel>} The current xy coordinate of the mouse, adjusted
     *                      for offsets
     */
    getMousePosition: function (evt) {
        if (!this.includeXY) {
            this.clearMouseCache();
        } else if (!this.element.hasScrollEvent) {
            OpenLayers.Event.observe(window, "scroll", this.clearMouseListener);
            this.element.hasScrollEvent = true;
        }
        
        if (!this.element.scrolls) {
            var viewportElement = OpenLayers.Util.getViewportElement();
            this.element.scrolls = [
                window.pageXOffset || viewportElement.scrollLeft,
                window.pageYOffset || viewportElement.scrollTop
            ];
        }

        if (!this.element.lefttop) {
            this.element.lefttop = [
                (document.documentElement.clientLeft || 0),
                (document.documentElement.clientTop  || 0)
            ];
        }
        
        if (!this.element.offsets) {
            this.element.offsets = OpenLayers.Util.pagePosition(this.element);
        }

        return new OpenLayers.Pixel(
            (evt.clientX + this.element.scrolls[0]) - this.element.offsets[0]
                         - this.element.lefttop[0], 
            (evt.clientY + this.element.scrolls[1]) - this.element.offsets[1]
                         - this.element.lefttop[1]
        ); 
    },

    /**
     * Method: addMsTouchListener
     *
     * Parameters:
     * element - {DOMElement} The DOM element to register the listener on
     * type - {String} The event type
     * handler - {Function} the handler
     */
    addMsTouchListener: function (element, type, handler) {
        var eventHandler = this.eventHandler;
        var touches = this._msTouches;

        function msHandler(evt) {
            handler(OpenLayers.Util.applyDefaults({
                stopPropagation: function() {
                    for (var i=touches.length-1; i>=0; --i) {
                        touches[i].stopPropagation();
                    }
                },
                preventDefault: function() {
                    for (var i=touches.length-1; i>=0; --i) {
                        touches[i].preventDefault();
                    }
                },
                type: type
            }, evt));
        }

        switch (type) {
            case 'touchstart':
                return this.addMsTouchListenerStart(element, type, msHandler);
            case 'touchend':
                return this.addMsTouchListenerEnd(element, type, msHandler);
            case 'touchmove':
                return this.addMsTouchListenerMove(element, type, msHandler);
            default:
                throw 'Unknown touch event type';
        }
    },

    /**
     * Method: addMsTouchListenerStart
     *
     * Parameters:
     * element - {DOMElement} The DOM element to register the listener on
     * type - {String} The event type
     * handler - {Function} the handler
     */
    addMsTouchListenerStart: function(element, type, handler) {
        var touches = this._msTouches;

        var cb = function(e) {

            var alreadyInArray = false;
            for (var i=0, ii=touches.length; i<ii; ++i) {
                if (touches[i].pointerId == e.pointerId) {
                    alreadyInArray = true;
                    break;
                }
            }
            if (!alreadyInArray) {
                touches.push(e);
            }

            e.touches = touches.slice();
            handler(e);
        };

        OpenLayers.Event.observe(element, 'MSPointerDown', cb);

        // Need to also listen for end events to keep the _msTouches list
        // accurate
        var internalCb = function(e) {
            for (var i=0, ii=touches.length; i<ii; ++i) {
                if (touches[i].pointerId == e.pointerId) {
                    touches.splice(i, 1);
                    break;
                }
            }
        };
        OpenLayers.Event.observe(element, 'MSPointerUp', internalCb);
    },

    /**
     * Method: addMsTouchListenerMove
     *
     * Parameters:
     * element - {DOMElement} The DOM element to register the listener on
     * type - {String} The event type
     * handler - {Function} the handler
     */
    addMsTouchListenerMove: function (element, type, handler) {
        var touches = this._msTouches;
        var cb = function(e) {

            //Don't fire touch moves when mouse isn't down
            if (e.pointerType == e.MSPOINTER_TYPE_MOUSE && e.buttons == 0) {
                return;
            }

            if (touches.length == 1 && touches[0].pageX == e.pageX &&
                    touches[0].pageY == e.pageY) {
                // don't trigger event when pointer has not moved
                return;
            }
            for (var i=0, ii=touches.length; i<ii; ++i) {
                if (touches[i].pointerId == e.pointerId) {
                    touches[i] = e;
                    break;
                }
            }

            e.touches = touches.slice();
            handler(e);
        };

        OpenLayers.Event.observe(element, 'MSPointerMove', cb);
    },

    /**
     * Method: addMsTouchListenerEnd
     *
     * Parameters:
     * element - {DOMElement} The DOM element to register the listener on
     * type - {String} The event type
     * handler - {Function} the handler
     */
    addMsTouchListenerEnd: function (element, type, handler) {
        var touches = this._msTouches;

        var cb = function(e) {

            for (var i=0, ii=touches.length; i<ii; ++i) {
                if (touches[i].pointerId == e.pointerId) {
                    touches.splice(i, 1);
                    break;
                }
            }
            
            e.touches = touches.slice();
            handler(e);
        };

        OpenLayers.Event.observe(element, 'MSPointerUp', cb);
    },

    CLASS_NAME: "OpenLayers.Events"
});
/* ======================================================================
    OpenLayers/Animation.js
   ====================================================================== */

/* Copyright (c) 2006-2013 by OpenLayers Contributors (see authors.txt for
 * full list of contributors). Published under the 2-clause BSD license.
 * See license.txt in the OpenLayers distribution or repository for the
 * full text of the license. */

/**
 * @requires OpenLayers/SingleFile.js
 * @requires OpenLayers/Util/vendorPrefix.js
 */

/**
 * Namespace: OpenLayers.Animation
 * A collection of utility functions for executing methods that repaint a 
 *     portion of the browser window.  These methods take advantage of the
 *     browser's scheduled repaints where requestAnimationFrame is available.
 */
OpenLayers.Animation = (function(window) {
    
    /**
     * Property: isNative
     * {Boolean} true if a native requestAnimationFrame function is available
     */
    var requestAnimationFrame = OpenLayers.Util.vendorPrefix.js(window, "requestAnimationFrame");
    var isNative = !!(requestAnimationFrame);
    
    /**
     * Function: requestFrame
     * Schedule a function to be called at the next available animation frame.
     *     Uses the native method where available.  Where requestAnimationFrame is
     *     not available, setTimeout will be called with a 16ms delay.
     *
     * Parameters:
     * callback - {Function} The function to be called at the next animation frame.
     * element - {DOMElement} Optional element that visually bounds the animation.
     */
    var requestFrame = (function() {
        var request = window[requestAnimationFrame] ||
            function(callback, element) {
                window.setTimeout(callback, 16);
            };
        // bind to window to avoid illegal invocation of native function
        return function(callback, element) {
            request.apply(window, [callback, element]);
        };
    })();
    
    // private variables for animation loops
    var counter = 0;
    var loops = {};
    
    /**
     * Function: start
     * Executes a method with <requestFrame> in series for some 
     *     duration.
     *
     * Parameters:
     * callback - {Function} The function to be called at the next animation frame.
     * duration - {Number} Optional duration for the loop.  If not provided, the
     *     animation loop will execute indefinitely.
     * element - {DOMElement} Optional element that visually bounds the animation.
     *
     * Returns:
     * {Number} Identifier for the animation loop.  Used to stop animations with
     *     <stop>.
     */
    function start(callback, duration, element) {
        duration = duration > 0 ? duration : Number.POSITIVE_INFINITY;
        var id = ++counter;
        var start = +new Date;
        loops[id] = function() {
            if (loops[id] && +new Date - start <= duration) {
                callback();
                if (loops[id]) {
                    requestFrame(loops[id], element);
                }
            } else {
                delete loops[id];
            }
        };
        requestFrame(loops[id], element);
        return id;
    }
    
    /**
     * Function: stop
     * Terminates an animation loop started with <start>.
     *
     * Parameters:
     * id - {Number} Identifier returned from <start>.
     */
    function stop(id) {
        delete loops[id];
    }
    
    return {
        isNative: isNative,
        requestFrame: requestFrame,
        start: start,
        stop: stop
    };
    
})(window);
/* ======================================================================
    OpenLayers/Tween.js
   ====================================================================== */

/* Copyright (c) 2006-2013 by OpenLayers Contributors (see authors.txt for
 * full list of contributors). Published under the 2-clause BSD license.
 * See license.txt in the OpenLayers distribution or repository for the
 * full text of the license. */

/**
 * @requires OpenLayers/BaseTypes/Class.js
 * @requires OpenLayers/Animation.js
 */

/**
 * Namespace: OpenLayers.Tween
 */
OpenLayers.Tween = OpenLayers.Class({
    
    /**
     * APIProperty: easing
     * {<OpenLayers.Easing>(Function)} Easing equation used for the animation
     *     Defaultly set to OpenLayers.Easing.Expo.easeOut
     */
    easing: null,
    
    /**
     * APIProperty: begin
     * {Object} Values to start the animation with
     */
    begin: null,
    
    /**
     * APIProperty: finish
     * {Object} Values to finish the animation with
     */
    finish: null,
    
    /**
     * APIProperty: duration
     * {int} duration of the tween (number of steps)
     */
    duration: null,
    
    /**
     * APIProperty: callbacks
     * {Object} An object with start, eachStep and done properties whose values
     *     are functions to be call during the animation. They are passed the
     *     current computed value as argument.
     */
    callbacks: null,
    
    /**
     * Property: time
     * {int} Step counter
     */
    time: null,
    
    /**
     * APIProperty: minFrameRate
     * {Number} The minimum framerate for animations in frames per second. After
     * each step, the time spent in the animation is compared to the calculated
     * time at this frame rate. If the animation runs longer than the calculated
     * time, the next step is skipped. Default is 30.
     */
    minFrameRate: null,

    /**
     * Property: startTime
     * {Number} The timestamp of the first execution step. Used for skipping
     * frames
     */
    startTime: null,
    
    /**
     * Property: animationId
     * {int} Loop id returned by OpenLayers.Animation.start
     */
    animationId: null,
    
    /**
     * Property: playing
     * {Boolean} Tells if the easing is currently playing
     */
    playing: false,
    
    /** 
     * Constructor: OpenLayers.Tween
     * Creates a Tween.
     *
     * Parameters:
     * easing - {<OpenLayers.Easing>(Function)} easing function method to use
     */ 
    initialize: function(easing) {
        this.easing = (easing) ? easing : OpenLayers.Easing.Expo.easeOut;
    },
    
    /**
     * APIMethod: start
     * Plays the Tween, and calls the callback method on each step
     * 
     * Parameters:
     * begin - {Object} values to start the animation with
     * finish - {Object} values to finish the animation with
     * duration - {int} duration of the tween (number of steps)
     * options - {Object} hash of options (callbacks (start, eachStep, done),
     *     minFrameRate)
     */
    start: function(begin, finish, duration, options) {
        this.playing = true;
        this.begin = begin;
        this.finish = finish;
        this.duration = duration;
        this.callbacks = options.callbacks;
        this.minFrameRate = options.minFrameRate || 30;
        this.time = 0;
        this.startTime = new Date().getTime();
        OpenLayers.Animation.stop(this.animationId);
        this.animationId = null;
        if (this.callbacks && this.callbacks.start) {
            this.callbacks.start.call(this, this.begin);
        }
        this.animationId = OpenLayers.Animation.start(
            OpenLayers.Function.bind(this.play, this)
        );
    },
    
    /**
     * APIMethod: stop
     * Stops the Tween, and calls the done callback
     *     Doesn't do anything if animation is already finished
     */
    stop: function() {
        if (!this.playing) {
            return;
        }
        
        if (this.callbacks && this.callbacks.done) {
            this.callbacks.done.call(this, this.finish);
        }
        OpenLayers.Animation.stop(this.animationId);
        this.animationId = null;
        this.playing = false;
    },
    
    /**
     * Method: play
     * Calls the appropriate easing method
     */
    play: function() {
        var value = {};
        for (var i in this.begin) {
            var b = this.begin[i];
            var f = this.finish[i];
            if (b == null || f == null || isNaN(b) || isNaN(f)) {
                throw new TypeError('invalid value for Tween');
            }

            var c = f - b;
            value[i] = this.easing.apply(this, [this.time, b, c, this.duration]);
        }
        this.time++;
        
        if (this.callbacks && this.callbacks.eachStep) {
            // skip frames if frame rate drops below threshold
            if ((new Date().getTime() - this.startTime) / this.time <= 1000 / this.minFrameRate) {
                this.callbacks.eachStep.call(this, value);
            }
        }
        
        if (this.time > this.duration) {
            this.stop();
        }
    },
    
    /**
     * Create empty functions for all easing methods.
     */
    CLASS_NAME: "OpenLayers.Tween"
});

/**
 * Namespace: OpenLayers.Easing
 * 
 * Credits:
 *      Easing Equations by Robert Penner, <http://www.robertpenner.com/easing/>
 */
OpenLayers.Easing = {
    /**
     * Create empty functions for all easing methods.
     */
    CLASS_NAME: "OpenLayers.Easing"
};

/**
 * Namespace: OpenLayers.Easing.Linear
 */
OpenLayers.Easing.Linear = {
    
    /**
     * Function: easeIn
     * 
     * Parameters:
     * t - {Float} time
     * b - {Float} beginning position
     * c - {Float} total change
     * d - {Float} duration of the transition
     *
     * Returns:
     * {Float}
     */
    easeIn: function(t, b, c, d) {
        return c*t/d + b;
    },
    
    /**
     * Function: easeOut
     * 
     * Parameters:
     * t - {Float} time
     * b - {Float} beginning position
     * c - {Float} total change
     * d - {Float} duration of the transition
     *
     * Returns:
     * {Float}
     */
    easeOut: function(t, b, c, d) {
        return c*t/d + b;
    },
    
    /**
     * Function: easeInOut
     * 
     * Parameters:
     * t - {Float} time
     * b - {Float} beginning position
     * c - {Float} total change
     * d - {Float} duration of the transition
     *
     * Returns:
     * {Float}
     */
    easeInOut: function(t, b, c, d) {
        return c*t/d + b;
    },

    CLASS_NAME: "OpenLayers.Easing.Linear"
};

/**
 * Namespace: OpenLayers.Easing.Expo
 */
OpenLayers.Easing.Expo = {
    
    /**
     * Function: easeIn
     * 
     * Parameters:
     * t - {Float} time
     * b - {Float} beginning position
     * c - {Float} total change
     * d - {Float} duration of the transition
     *
     * Returns:
     * {Float}
     */
    easeIn: function(t, b, c, d) {
        return (t==0) ? b : c * Math.pow(2, 10 * (t/d - 1)) + b;
    },
    
    /**
     * Function: easeOut
     * 
     * Parameters:
     * t - {Float} time
     * b - {Float} beginning position
     * c - {Float} total change
     * d - {Float} duration of the transition
     *
     * Returns:
     * {Float}
     */
    easeOut: function(t, b, c, d) {
        return (t==d) ? b+c : c * (-Math.pow(2, -10 * t/d) + 1) + b;
    },
    
    /**
     * Function: easeInOut
     * 
     * Parameters:
     * t - {Float} time
     * b - {Float} beginning position
     * c - {Float} total change
     * d - {Float} duration of the transition
     *
     * Returns:
     * {Float}
     */
    easeInOut: function(t, b, c, d) {
        if (t==0) return b;
        if (t==d) return b+c;
        if ((t/=d/2) < 1) return c/2 * Math.pow(2, 10 * (t - 1)) + b;
        return c/2 * (-Math.pow(2, -10 * --t) + 2) + b;
    },

    CLASS_NAME: "OpenLayers.Easing.Expo"
};

/**
 * Namespace: OpenLayers.Easing.Quad
 */
OpenLayers.Easing.Quad = {
    
    /**
     * Function: easeIn
     * 
     * Parameters:
     * t - {Float} time
     * b - {Float} beginning position
     * c - {Float} total change
     * d - {Float} duration of the transition
     *
     * Returns:
     * {Float}
     */
    easeIn: function(t, b, c, d) {
        return c*(t/=d)*t + b;
    },
    
    /**
     * Function: easeOut
     * 
     * Parameters:
     * t - {Float} time
     * b - {Float} beginning position
     * c - {Float} total change
     * d - {Float} duration of the transition
     *
     * Returns:
     * {Float}
     */
    easeOut: function(t, b, c, d) {
        return -c *(t/=d)*(t-2) + b;
    },
    
    /**
     * Function: easeInOut
     * 
     * Parameters:
     * t - {Float} time
     * b - {Float} beginning position
     * c - {Float} total change
     * d - {Float} duration of the transition
     *
     * Returns:
     * {Float}
     */
    easeInOut: function(t, b, c, d) {
        if ((t/=d/2) < 1) return c/2*t*t + b;
        return -c/2 * ((--t)*(t-2) - 1) + b;
    },

    CLASS_NAME: "OpenLayers.Easing.Quad"
};
/* ======================================================================
    OpenLayers/Projection.js
   ====================================================================== */

/* Copyright (c) 2006-2013 by OpenLayers Contributors (see authors.txt for
 * full list of contributors). Published under the 2-clause BSD license.
 * See license.txt in the OpenLayers distribution or repository for the
 * full text of the license. */

/**
 * @requires OpenLayers/BaseTypes/Class.js
 * @requires OpenLayers/Util.js
 */

/**
 * Namespace: OpenLayers.Projection
 * Methods for coordinate transforms between coordinate systems.  By default,
 *     OpenLayers ships with the ability to transform coordinates between
 *     geographic (EPSG:4326) and web or spherical mercator (EPSG:900913 et al.)
 *     coordinate reference systems.  See the <transform> method for details
 *     on usage.
 *
 * Additional transforms may be added by using the <proj4js at http://proj4js.org/>
 *     library.  If the proj4js library is included, the <transform> method 
 *     will work between any two coordinate reference systems with proj4js 
 *     definitions.
 *
 * If the proj4js library is not included, or if you wish to allow transforms
 *     between arbitrary coordinate reference systems, use the <addTransform>
 *     method to register a custom transform method.
 */
OpenLayers.Projection = OpenLayers.Class({

    /**
     * Property: proj
     * {Object} Proj4js.Proj instance.
     */
    proj: null,
    
    /**
     * Property: projCode
     * {String}
     */
    projCode: null,
    
    /**
     * Property: titleRegEx
     * {RegExp} regular expression to strip the title from a proj4js definition
     */
    titleRegEx: /\+title=[^\+]*/,

    /**
     * Constructor: OpenLayers.Projection
     * This class offers several methods for interacting with a wrapped 
     *     pro4js projection object. 
     *
     * Parameters:
     * projCode - {String} A string identifying the Well Known Identifier for
     *    the projection.
     * options - {Object} An optional object to set additional properties
     *     on the projection.
     *
     * Returns:
     * {<OpenLayers.Projection>} A projection object.
     */
    initialize: function(projCode, options) {
        OpenLayers.Util.extend(this, options);
        this.projCode = projCode;
        if (typeof Proj4js == "object") {
            this.proj = new Proj4js.Proj(projCode);
        }
    },
    
    /**
     * APIMethod: getCode
     * Get the string SRS code.
     *
     * Returns:
     * {String} The SRS code.
     */
    getCode: function() {
        return this.proj ? this.proj.srsCode : this.projCode;
    },
   
    /**
     * APIMethod: getUnits
     * Get the units string for the projection -- returns null if 
     *     proj4js is not available.
     *
     * Returns:
     * {String} The units abbreviation.
     */
    getUnits: function() {
        return this.proj ? this.proj.units : null;
    },

    /**
     * Method: toString
     * Convert projection to string (getCode wrapper).
     *
     * Returns:
     * {String} The projection code.
     */
    toString: function() {
        return this.getCode();
    },

    /**
     * Method: equals
     * Test equality of two projection instances.  Determines equality based
     *     soley on the projection code.
     *
     * Returns:
     * {Boolean} The two projections are equivalent.
     */
    equals: function(projection) {
        var p = projection, equals = false;
        if (p) {
            if (!(p instanceof OpenLayers.Projection)) {
                p = new OpenLayers.Projection(p);
            }
            if ((typeof Proj4js == "object") && this.proj.defData && p.proj.defData) {
                equals = this.proj.defData.replace(this.titleRegEx, "") ==
                    p.proj.defData.replace(this.titleRegEx, "");
            } else if (p.getCode) {
                var source = this.getCode(), target = p.getCode();
                equals = source == target ||
                    !!OpenLayers.Projection.transforms[source] &&
                    OpenLayers.Projection.transforms[source][target] ===
                        OpenLayers.Projection.nullTransform;
            }
        }
        return equals;   
    },

    /* Method: destroy
     * Destroy projection object.
     */
    destroy: function() {
        delete this.proj;
        delete this.projCode;
    },
    
    CLASS_NAME: "OpenLayers.Projection" 
});     

/**
 * Property: transforms
 * {Object} Transforms is an object, with from properties, each of which may
 * have a to property. This allows you to define projections without 
 * requiring support for proj4js to be included.
 *
 * This object has keys which correspond to a 'source' projection object.  The
 * keys should be strings, corresponding to the projection.getCode() value.
 * Each source projection object should have a set of destination projection
 * keys included in the object. 
 * 
 * Each value in the destination object should be a transformation function,
 * where the function is expected to be passed an object with a .x and a .y
 * property.  The function should return the object, with the .x and .y
 * transformed according to the transformation function.
 *
 * Note - Properties on this object should not be set directly.  To add a
 *     transform method to this object, use the <addTransform> method.  For an
 *     example of usage, see the OpenLayers.Layer.SphericalMercator file.
 */
OpenLayers.Projection.transforms = {};

/**
 * APIProperty: defaults
 * {Object} Defaults for the SRS codes known to OpenLayers (currently
 * EPSG:4326, CRS:84, urn:ogc:def:crs:EPSG:6.6:4326, EPSG:900913, EPSG:3857,
 * EPSG:102113 and EPSG:102100). Keys are the SRS code, values are units,
 * maxExtent (the validity extent for the SRS) and yx (true if this SRS is
 * known to have a reverse axis order).
 */
OpenLayers.Projection.defaults = {
    "EPSG:4326": {
        units: "degrees",
        maxExtent: [-180, -90, 180, 90],
        yx: true
    },
    "CRS:84": {
        units: "degrees",
        maxExtent: [-180, -90, 180, 90]
    },
    "EPSG:900913": {
        units: "m",
        maxExtent: [-20037508.34, -20037508.34, 20037508.34, 20037508.34]
    }
};

/**
 * APIMethod: addTransform
 * Set a custom transform method between two projections.  Use this method in
 *     cases where the proj4js lib is not available or where custom projections
 *     need to be handled.
 *
 * Parameters:
 * from - {String} The code for the source projection
 * to - {String} the code for the destination projection
 * method - {Function} A function that takes a point as an argument and
 *     transforms that point from the source to the destination projection
 *     in place.  The original point should be modified.
 */
OpenLayers.Projection.addTransform = function(from, to, method) {
    if (method === OpenLayers.Projection.nullTransform) {
        var defaults = OpenLayers.Projection.defaults[from];
        if (defaults && !OpenLayers.Projection.defaults[to]) {
            OpenLayers.Projection.defaults[to] = defaults;
        }
    }
    if(!OpenLayers.Projection.transforms[from]) {
        OpenLayers.Projection.transforms[from] = {};
    }
    OpenLayers.Projection.transforms[from][to] = method;
};

/**
 * APIMethod: transform
 * Transform a point coordinate from one projection to another.  Note that
 *     the input point is transformed in place.
 * 
 * Parameters:
 * point - {<OpenLayers.Geometry.Point> | Object} An object with x and y
 *     properties representing coordinates in those dimensions.
 * source - {OpenLayers.Projection} Source map coordinate system
 * dest - {OpenLayers.Projection} Destination map coordinate system
 *
 * Returns:
 * point - {object} A transformed coordinate.  The original point is modified.
 */
OpenLayers.Projection.transform = function(point, source, dest) {
    if (source && dest) {
        if (!(source instanceof OpenLayers.Projection)) {
            source = new OpenLayers.Projection(source);
        }
        if (!(dest instanceof OpenLayers.Projection)) {
            dest = new OpenLayers.Projection(dest);
        }
        if (source.proj && dest.proj) {
            point = Proj4js.transform(source.proj, dest.proj, point);
        } else {
            var sourceCode = source.getCode();
            var destCode = dest.getCode();
            var transforms = OpenLayers.Projection.transforms;
            if (transforms[sourceCode] && transforms[sourceCode][destCode]) {
                transforms[sourceCode][destCode](point);
            }
        }
    }
    return point;
};

/**
 * APIFunction: nullTransform
 * A null transformation - useful for defining projection aliases when
 * proj4js is not available:
 *
 * (code)
 * OpenLayers.Projection.addTransform("EPSG:3857", "EPSG:900913",
 *     OpenLayers.Projection.nullTransform);
 * OpenLayers.Projection.addTransform("EPSG:900913", "EPSG:3857",
 *     OpenLayers.Projection.nullTransform);
 * (end)
 */
OpenLayers.Projection.nullTransform = function(point) {
    return point;
};

/**
 * Note: Transforms for web mercator <-> geographic
 * OpenLayers recognizes EPSG:3857, EPSG:900913, EPSG:102113 and EPSG:102100.
 * OpenLayers originally started referring to EPSG:900913 as web mercator.
 * The EPSG has declared EPSG:3857 to be web mercator.
 * ArcGIS 10 recognizes the EPSG:3857, EPSG:102113, and EPSG:102100 as
 * equivalent.  See http://blogs.esri.com/Dev/blogs/arcgisserver/archive/2009/11/20/ArcGIS-Online-moving-to-Google-_2F00_-Bing-tiling-scheme_3A00_-What-does-this-mean-for-you_3F00_.aspx#12084.
 * For geographic, OpenLayers recognizes EPSG:4326, CRS:84 and
 * urn:ogc:def:crs:EPSG:6.6:4326. OpenLayers also knows about the reverse axis
 * order for EPSG:4326. 
 */
(function() {

    var pole = 20037508.34;

    function inverseMercator(xy) {
        xy.x = 180 * xy.x / pole;
        xy.y = 180 / Math.PI * (2 * Math.atan(Math.exp((xy.y / pole) * Math.PI)) - Math.PI / 2);
        return xy;
    }

    function forwardMercator(xy) {
        xy.x = xy.x * pole / 180;
        var y = Math.log(Math.tan((90 + xy.y) * Math.PI / 360)) / Math.PI * pole;
        xy.y = Math.max(-20037508.34, Math.min(y, 20037508.34));
        return xy;
    }

    function map(base, codes) {
        var add = OpenLayers.Projection.addTransform;
        var same = OpenLayers.Projection.nullTransform;
        var i, len, code, other, j;
        for (i=0, len=codes.length; i<len; ++i) {
            code = codes[i];
            add(base, code, forwardMercator);
            add(code, base, inverseMercator);
            for (j=i+1; j<len; ++j) {
                other = codes[j];
                add(code, other, same);
                add(other, code, same);
            }
        }
    }
    
    // list of equivalent codes for web mercator
    var mercator = ["EPSG:900913", "EPSG:3857", "EPSG:102113", "EPSG:102100"],
        geographic = ["CRS:84", "urn:ogc:def:crs:EPSG:6.6:4326", "EPSG:4326"],
        i;
    for (i=mercator.length-1; i>=0; --i) {
        map(mercator[i], geographic);
    }
    for (i=geographic.length-1; i>=0; --i) {
        map(geographic[i], mercator);
    }

})();
/* ======================================================================
    OpenLayers/Map.js
   ====================================================================== */

/* Copyright (c) 2006-2013 by OpenLayers Contributors (see authors.txt for
 * full list of contributors). Published under the 2-clause BSD license.
 * See license.txt in the OpenLayers distribution or repository for the
 * full text of the license. */

/**
 * @requires OpenLayers/BaseTypes/Class.js
 * @requires OpenLayers/Util.js
 * @requires OpenLayers/Util/vendorPrefix.js
 * @requires OpenLayers/Events.js
 * @requires OpenLayers/Tween.js
 * @requires OpenLayers/Projection.js
 */

/**
 * Class: OpenLayers.Map
 * Instances of OpenLayers.Map are interactive maps embedded in a web page.
 * Create a new map with the <OpenLayers.Map> constructor.
 * 
 * On their own maps do not provide much functionality.  To extend a map
 * it's necessary to add controls (<OpenLayers.Control>) and 
 * layers (<OpenLayers.Layer>) to the map. 
 */
OpenLayers.Map = OpenLayers.Class({
    
    /**
     * Constant: Z_INDEX_BASE
     * {Object} Base z-indexes for different classes of thing 
     */
    Z_INDEX_BASE: {
        BaseLayer: 100,
        Overlay: 325,
        Feature: 725,
        Popup: 750,
        Control: 1000
    },

    /**
     * APIProperty: events
     * {<OpenLayers.Events>}
     *
     * Register a listener for a particular event with the following syntax:
     * (code)
     * map.events.register(type, obj, listener);
     * (end)
     *
     * Listeners will be called with a reference to an event object.  The
     *     properties of this event depends on exactly what happened.
     *
     * All event objects have at least the following properties:
     * object - {Object} A reference to map.events.object.
     * element - {DOMElement} A reference to map.events.element.
     *
     * Browser events have the following additional properties:
     * xy - {<OpenLayers.Pixel>} The pixel location of the event (relative
     *     to the the map viewport).
     *
     * Supported map event types:
     * preaddlayer - triggered before a layer has been added.  The event
     *     object will include a *layer* property that references the layer  
     *     to be added. When a listener returns "false" the adding will be 
     *     aborted.
     * addlayer - triggered after a layer has been added.  The event object
     *     will include a *layer* property that references the added layer.
     * preremovelayer - triggered before a layer has been removed. The event
     *     object will include a *layer* property that references the layer  
     *     to be removed. When a listener returns "false" the removal will be 
     *     aborted.
     * removelayer - triggered after a layer has been removed.  The event
     *     object will include a *layer* property that references the removed
     *     layer.
     * changelayer - triggered after a layer name change, order change,
     *     opacity change, params change, visibility change (actual visibility,
     *     not the layer's visibility property) or attribution change (due to
     *     extent change). Listeners will receive an event object with *layer*
     *     and *property* properties. The *layer* property will be a reference
     *     to the changed layer. The *property* property will be a key to the
     *     changed property (name, order, opacity, params, visibility or
     *     attribution).
     * movestart - triggered after the start of a drag, pan, or zoom. The event
     *     object may include a *zoomChanged* property that tells whether the
     *     zoom has changed.
     * move - triggered after each drag, pan, or zoom
     * moveend - triggered after a drag, pan, or zoom completes
     * zoomend - triggered after a zoom completes
     * mouseover - triggered after mouseover the map
     * mouseout - triggered after mouseout the map
     * mousemove - triggered after mousemove the map
     * changebaselayer - triggered after the base layer changes
     * updatesize - triggered after the <updateSize> method was executed
     */

    /**
     * Property: id
     * {String} Unique identifier for the map
     */
    id: null,
    
    /**
     * Property: fractionalZoom
     * {Boolean} For a base layer that supports it, allow the map resolution
     *     to be set to a value between one of the values in the resolutions
     *     array.  Default is false.
     *
     * When fractionalZoom is set to true, it is possible to zoom to
     *     an arbitrary extent.  This requires a base layer from a source
     *     that supports requests for arbitrary extents (i.e. not cached
     *     tiles on a regular lattice).  This means that fractionalZoom
     *     will not work with commercial layers (Google, Yahoo, VE), layers
     *     using TileCache, or any other pre-cached data sources.
     *
     * If you are using fractionalZoom, then you should also use
     *     <getResolutionForZoom> instead of layer.resolutions[zoom] as the
     *     former works for non-integer zoom levels.
     */
    fractionalZoom: false,
    
    /**
     * APIProperty: events
     * {<OpenLayers.Events>} An events object that handles all 
     *                       events on the map
     */
    events: null,
    
    /**
     * APIProperty: allOverlays
     * {Boolean} Allow the map to function with "overlays" only.  Defaults to
     *     false.  If true, the lowest layer in the draw order will act as
     *     the base layer.  In addition, if set to true, all layers will
     *     have isBaseLayer set to false when they are added to the map.
     *
     * Note:
     * If you set map.allOverlays to true, then you *cannot* use
     *     map.setBaseLayer or layer.setIsBaseLayer.  With allOverlays true,
     *     the lowest layer in the draw layer is the base layer.  So, to change
     *     the base layer, use <setLayerIndex> or <raiseLayer> to set the layer
     *     index to 0.
     */
    allOverlays: false,

    /**
     * APIProperty: div
     * {DOMElement|String} The element that contains the map (or an id for
     *     that element).  If the <OpenLayers.Map> constructor is called
     *     with two arguments, this should be provided as the first argument.
     *     Alternatively, the map constructor can be called with the options
     *     object as the only argument.  In this case (one argument), a
     *     div property may or may not be provided.  If the div property
     *     is not provided, the map can be rendered to a container later
     *     using the <render> method.
     *     
     * Note:
     * If you are calling <render> after map construction, do not use
     *     <maxResolution>  auto.  Instead, divide your <maxExtent> by your
     *     maximum expected dimension.
     */
    div: null,
    
    /**
     * Property: dragging
     * {Boolean} The map is currently being dragged.
     */
    dragging: false,

    /**
     * Property: size
     * {<OpenLayers.Size>} Size of the main div (this.div)
     */
    size: null,
    
    /**
     * Property: viewPortDiv
     * {HTMLDivElement} The element that represents the map viewport
     */
    viewPortDiv: null,

    /**
     * Property: layerContainerOrigin
     * {<OpenLayers.LonLat>} The lonlat at which the later container was
     *                       re-initialized (on-zoom)
     */
    layerContainerOrigin: null,

    /**
     * Property: layerContainerDiv
     * {HTMLDivElement} The element that contains the layers.
     */
    layerContainerDiv: null,

    /**
     * APIProperty: layers
     * {Array(<OpenLayers.Layer>)} Ordered list of layers in the map
     */
    layers: null,

    /**
     * APIProperty: controls
     * {Array(<OpenLayers.Control>)} List of controls associated with the map.
     *
     * If not provided in the map options at construction, the map will
     *     by default be given the following controls if present in the build:
     *  - <OpenLayers.Control.Navigation> or <OpenLayers.Control.TouchNavigation>
     *  - <OpenLayers.Control.Zoom> or <OpenLayers.Control.PanZoom>
     *  - <OpenLayers.Control.ArgParser>
     *  - <OpenLayers.Control.Attribution>
     */
    controls: null,

    /**
     * Property: popups
     * {Array(<OpenLayers.Popup>)} List of popups associated with the map
     */
    popups: null,

    /**
     * APIProperty: baseLayer
     * {<OpenLayers.Layer>} The currently selected base layer.  This determines
     * min/max zoom level, projection, etc.
     */
    baseLayer: null,
    
    /**
     * Property: center
     * {<OpenLayers.LonLat>} The current center of the map
     */
    center: null,

    /**
     * Property: resolution
     * {Float} The resolution of the map.
     */
    resolution: null,

    /**
     * Property: zoom
     * {Integer} The current zoom level of the map
     */
    zoom: 0,    

    /**
     * Property: panRatio
     * {Float} The ratio of the current extent within
     *         which panning will tween.
     */
    panRatio: 1.5,    

    /**
     * APIProperty: options
     * {Object} The options object passed to the class constructor. Read-only.
     */
    options: null,

  // Options

    /**
     * APIProperty: tileSize
     * {<OpenLayers.Size>} Set in the map options to override the default tile
     *                     size for this map.
     */
    tileSize: null,

    /**
     * APIProperty: projection
     * {String} Set in the map options to specify the default projection 
     *          for layers added to this map. When using a projection other than EPSG:4326
     *          (CRS:84, Geographic) or EPSG:3857 (EPSG:900913, Web Mercator),
     *          also set maxExtent, maxResolution or resolutions.  Default is "EPSG:4326".
     *          Note that the projection of the map is usually determined
     *          by that of the current baseLayer (see <baseLayer> and <getProjectionObject>).
     */
    projection: "EPSG:4326",    
        
    /**
     * APIProperty: units
     * {String} The map units.  Possible values are 'degrees' (or 'dd'), 'm', 
     *     'ft', 'km', 'mi', 'inches'.  Normally taken from the projection.
     *     Only required if both map and layers do not define a projection,
     *     or if they define a projection which does not define units
     */
    units: null,

    /**
     * APIProperty: resolutions
     * {Array(Float)} A list of map resolutions (map units per pixel) in 
     *     descending order.  If this is not set in the layer constructor, it 
     *     will be set based on other resolution related properties 
     *     (maxExtent, maxResolution, maxScale, etc.).
     */
    resolutions: null,

    /**
     * APIProperty: maxResolution
     * {Float} Required if you are not displaying the whole world on a tile
     * with the size specified in <tileSize>.
     */
    maxResolution: null,

    /**
     * APIProperty: minResolution
     * {Float}
     */
    minResolution: null,

    /**
     * APIProperty: maxScale
     * {Float}
     */
    maxScale: null,

    /**
     * APIProperty: minScale
     * {Float}
     */
    minScale: null,

    /**
     * APIProperty: maxExtent
     * {<OpenLayers.Bounds>|Array} If provided as an array, the array
     *     should consist of four values (left, bottom, right, top).
     *     The maximum extent for the map.
     *     Default depends on projection; if this is one of those defined in OpenLayers.Projection.defaults
     *     (EPSG:4326 or web mercator), maxExtent will be set to the value defined there;
     *     else, defaults to null.
     *     To restrict user panning and zooming of the map, use <restrictedExtent> instead.
     *     The value for <maxExtent> will change calculations for tile URLs.
     */
    maxExtent: null,
    
    /**
     * APIProperty: minExtent
     * {<OpenLayers.Bounds>|Array} If provided as an array, the array
     *     should consist of four values (left, bottom, right, top).
     *     The minimum extent for the map.  Defaults to null.
     */
    minExtent: null,
    
    /**
     * APIProperty: restrictedExtent
     * {<OpenLayers.Bounds>|Array} If provided as an array, the array
     *     should consist of four values (left, bottom, right, top).
     *     Limit map navigation to this extent where possible.
     *     If a non-null restrictedExtent is set, panning will be restricted
     *     to the given bounds.  In addition, zooming to a resolution that
     *     displays more than the restricted extent will center the map
     *     on the restricted extent.  If you wish to limit the zoom level
     *     or resolution, use maxResolution.
     */
    restrictedExtent: null,

    /**
     * APIProperty: numZoomLevels
     * {Integer} Number of zoom levels for the map.  Defaults to 16.  Set a
     *           different value in the map options if needed.
     */
    numZoomLevels: 16,

    /**
     * APIProperty: theme
     * {String} Relative path to a CSS file from which to load theme styles.
     *          Specify null in the map options (e.g. {theme: null}) if you 
     *          want to get cascading style declarations - by putting links to 
     *          stylesheets or style declarations directly in your page.
     */
    theme: null,
    
    /** 
     * APIProperty: displayProjection
     * {<OpenLayers.Projection>} Requires proj4js support for projections other
     *     than EPSG:4326 or EPSG:900913/EPSG:3857. Projection used by
     *     several controls to display data to user. If this property is set,
     *     it will be set on any control which has a null displayProjection
     *     property at the time the control is added to the map. 
     */
    displayProjection: null,

    /**
     * APIProperty: tileManager
     * {<OpenLayers.TileManager>|Object} By default, and if the build contains
     * TileManager.js, the map will use the TileManager to queue image requests
     * and to cache tile image elements. To create a map without a TileManager
     * configure the map with tileManager: null. To create a TileManager with
     * non-default options, supply the options instead or alternatively supply
     * an instance of {<OpenLayers.TileManager>}.
     */

    /**
     * APIProperty: fallThrough
     * {Boolean} Should OpenLayers allow events on the map to fall through to
     *           other elements on the page, or should it swallow them? (#457)
     *           Default is to swallow.
     */
    fallThrough: false,

    /**
     * APIProperty: autoUpdateSize
     * {Boolean} Should OpenLayers automatically update the size of the map
     * when the resize event is fired. Default is true.
     */
    autoUpdateSize: true,
    
    /**
     * APIProperty: eventListeners
     * {Object} If set as an option at construction, the eventListeners
     *     object will be registered with <OpenLayers.Events.on>.  Object
     *     structure must be a listeners object as shown in the example for
     *     the events.on method.
     */
    eventListeners: null,

    /**
     * Property: panTween
     * {<OpenLayers.Tween>} Animated panning tween object, see panTo()
     */
    panTween: null,

    /**
     * APIProperty: panMethod
     * {Function} The Easing function to be used for tweening.  Default is
     * OpenLayers.Easing.Expo.easeOut. Setting this to 'null' turns off
     * animated panning.
     */
    panMethod: OpenLayers.Easing.Expo.easeOut,
    
    /**
     * Property: panDuration
     * {Integer} The number of steps to be passed to the
     * OpenLayers.Tween.start() method when the map is
     * panned.
     * Default is 50.
     */
    panDuration: 50,
    
    /**
     * Property: zoomTween
     * {<OpenLayers.Tween>} Animated zooming tween object, see zoomTo()
     */
    zoomTween: null,

    /**
     * APIProperty: zoomMethod
     * {Function} The Easing function to be used for tweening.  Default is
     * OpenLayers.Easing.Quad.easeOut. Setting this to 'null' turns off
     * animated zooming.
     */
    zoomMethod: OpenLayers.Easing.Quad.easeOut,
    
    /**
     * Property: zoomDuration
     * {Integer} The number of steps to be passed to the
     * OpenLayers.Tween.start() method when the map is zoomed.
     * Default is 20.
     */
    zoomDuration: 20,
    
    /**
     * Property: paddingForPopups
     * {<OpenLayers.Bounds>} Outside margin of the popup. Used to prevent 
     *     the popup from getting too close to the map border.
     */
    paddingForPopups : null,
    
    /**
     * Property: layerContainerOriginPx
     * {Object} Cached object representing the layer container origin (in pixels).
     */
    layerContainerOriginPx: null,
    
    /**
     * Property: minPx
     * {Object} An object with a 'x' and 'y' values that is the lower
     *     left of maxExtent in viewport pixel space.
     *     Used to verify in moveByPx that the new location we're moving to
     *     is valid. It is also used in the getLonLatFromViewPortPx function
     *     of Layer.
     */
    minPx: null,
    
    /**
     * Property: maxPx
     * {Object} An object with a 'x' and 'y' values that is the top
     *     right of maxExtent in viewport pixel space.
     *     Used to verify in moveByPx that the new location we're moving to
     *     is valid.
     */
    maxPx: null,
    
    /**
     * Constructor: OpenLayers.Map
     * Constructor for a new OpenLayers.Map instance.  There are two possible
     *     ways to call the map constructor.  See the examples below.
     *
     * Parameters:
     * div - {DOMElement|String}  The element or id of an element in your page
     *     that will contain the map.  May be omitted if the <div> option is
     *     provided or if you intend to call the <render> method later.
     * options - {Object} Optional object with properties to tag onto the map.
     *
     * Valid options (in addition to the listed API properties):
     * center - {<OpenLayers.LonLat>|Array} The default initial center of the map.
     *     If provided as array, the first value is the x coordinate,
     *     and the 2nd value is the y coordinate.
     *     Only specify if <layers> is provided.
     *     Note that if an ArgParser/Permalink control is present,
     *     and the querystring contains coordinates, center will be set
     *     by that, and this option will be ignored.
     * zoom - {Number} The initial zoom level for the map. Only specify if
     *     <layers> is provided.
     *     Note that if an ArgParser/Permalink control is present,
     *     and the querystring contains a zoom level, zoom will be set
     *     by that, and this option will be ignored.
     * extent - {<OpenLayers.Bounds>|Array} The initial extent of the map.
     *     If provided as an array, the array should consist of
     *     four values (left, bottom, right, top).
     *     Only specify if <center> and <zoom> are not provided.
     * 
     * Examples:
     * (code)
     * // create a map with default options in an element with the id "map1"
     * var map = new OpenLayers.Map("map1");
     *
     * // create a map with non-default options in an element with id "map2"
     * var options = {
     *     projection: "EPSG:3857",
     *     maxExtent: new OpenLayers.Bounds(-200000, -200000, 200000, 200000),
     *     center: new OpenLayers.LonLat(-12356463.476333, 5621521.4854095)
     * };
     * var map = new OpenLayers.Map("map2", options);
     *
     * // map with non-default options - same as above but with a single argument,
     * // a restricted extent, and using arrays for bounds and center
     * var map = new OpenLayers.Map({
     *     div: "map_id",
     *     projection: "EPSG:3857",
     *     maxExtent: [-18924313.432222, -15538711.094146, 18924313.432222, 15538711.094146],
     *     restrictedExtent: [-13358338.893333, -9608371.5085962, 13358338.893333, 9608371.5085962],
     *     center: [-12356463.476333, 5621521.4854095]
     * });
     *
     * // create a map without a reference to a container - call render later
     * var map = new OpenLayers.Map({
     *     projection: "EPSG:3857",
     *     maxExtent: new OpenLayers.Bounds(-200000, -200000, 200000, 200000)
     * });
     * (end)
     */    
    initialize: function (div, options) {
        
        // If only one argument is provided, check if it is an object.
        if(arguments.length === 1 && typeof div === "object") {
            options = div;
            div = options && options.div;
        }

        // Simple-type defaults are set in class definition. 
        //  Now set complex-type defaults 
        this.tileSize = new OpenLayers.Size(OpenLayers.Map.TILE_WIDTH,
                                            OpenLayers.Map.TILE_HEIGHT);
        
        this.paddingForPopups = new OpenLayers.Bounds(15, 15, 15, 15);

        this.theme = OpenLayers._getScriptLocation() + 
                             'theme/default/style.css'; 

        // backup original options
        this.options = OpenLayers.Util.extend({}, options);

        // now override default options 
        OpenLayers.Util.extend(this, options);
        
        var projCode = this.projection instanceof OpenLayers.Projection ?
            this.projection.projCode : this.projection;
        OpenLayers.Util.applyDefaults(this, OpenLayers.Projection.defaults[projCode]);
        
        // allow extents and center to be arrays
        if (this.maxExtent && !(this.maxExtent instanceof OpenLayers.Bounds)) {
            this.maxExtent = new OpenLayers.Bounds(this.maxExtent);
        }
        if (this.minExtent && !(this.minExtent instanceof OpenLayers.Bounds)) {
            this.minExtent = new OpenLayers.Bounds(this.minExtent);
        }
        if (this.restrictedExtent && !(this.restrictedExtent instanceof OpenLayers.Bounds)) {
            this.restrictedExtent = new OpenLayers.Bounds(this.restrictedExtent);
        }
        if (this.center && !(this.center instanceof OpenLayers.LonLat)) {
            this.center = new OpenLayers.LonLat(this.center);
        }

        // initialize layers array
        this.layers = [];

        this.id = OpenLayers.Util.createUniqueID("OpenLayers.Map_");

        this.div = OpenLayers.Util.getElement(div);
        if(!this.div) {
            this.div = document.createElement("div");
            this.div.style.height = "1px";
            this.div.style.width = "1px";
        }
        
        OpenLayers.Element.addClass(this.div, 'olMap');

        // the viewPortDiv is the outermost div we modify
        var id = this.id + "_OpenLayers_ViewPort";
        this.viewPortDiv = OpenLayers.Util.createDiv(id, null, null, null,
                                                     "relative", null,
                                                     "hidden");
        this.viewPortDiv.style.width = "100%";
        this.viewPortDiv.style.height = "100%";
        this.viewPortDiv.className = "olMapViewport";
        this.div.appendChild(this.viewPortDiv);

        this.events = new OpenLayers.Events(
            this, this.viewPortDiv, null, this.fallThrough, 
            {includeXY: true}
        );
        
        if (OpenLayers.TileManager && this.tileManager !== null) {
            if (!(this.tileManager instanceof OpenLayers.TileManager)) {
                this.tileManager = new OpenLayers.TileManager(this.tileManager);
            }
            this.tileManager.addMap(this);
        }

        // the layerContainerDiv is the one that holds all the layers
        id = this.id + "_OpenLayers_Container";
        this.layerContainerDiv = OpenLayers.Util.createDiv(id);
        this.layerContainerDiv.style.zIndex=this.Z_INDEX_BASE['Popup']-1;
        this.layerContainerOriginPx = {x: 0, y: 0};
        this.applyTransform();
        
        this.viewPortDiv.appendChild(this.layerContainerDiv);

        this.updateSize();
        if(this.eventListeners instanceof Object) {
            this.events.on(this.eventListeners);
        }

        if (this.autoUpdateSize === true) {
            // updateSize on catching the window's resize
            // Note that this is ok, as updateSize() does nothing if the 
            // map's size has not actually changed.
            this.updateSizeDestroy = OpenLayers.Function.bind(this.updateSize, 
                this);
            OpenLayers.Event.observe(window, 'resize',
                            this.updateSizeDestroy);
        }
        
        // only append link stylesheet if the theme property is set
        if(this.theme) {
            // check existing links for equivalent url
            var addNode = true;
            var nodes = document.getElementsByTagName('link');
            for(var i=0, len=nodes.length; i<len; ++i) {
                if(OpenLayers.Util.isEquivalentUrl(nodes.item(i).href,
                                                   this.theme)) {
                    addNode = false;
                    break;
                }
            }
            // only add a new node if one with an equivalent url hasn't already
            // been added
            if(addNode) {
                var cssNode = document.createElement('link');
                cssNode.setAttribute('rel', 'stylesheet');
                cssNode.setAttribute('type', 'text/css');
                cssNode.setAttribute('href', this.theme);
                document.getElementsByTagName('head')[0].appendChild(cssNode);
            }
        }
        
        if (this.controls == null) { // default controls
            this.controls = [];
            if (OpenLayers.Control != null) { // running full or lite?
                // Navigation or TouchNavigation depending on what is in build
                if (OpenLayers.Control.Navigation) {
                    this.controls.push(new OpenLayers.Control.Navigation());
                } else if (OpenLayers.Control.TouchNavigation) {
                    this.controls.push(new OpenLayers.Control.TouchNavigation());
                }
                if (OpenLayers.Control.Zoom) {
                    this.controls.push(new OpenLayers.Control.Zoom());
                } else if (OpenLayers.Control.PanZoom) {
                    this.controls.push(new OpenLayers.Control.PanZoom());
                }

                if (OpenLayers.Control.ArgParser) {
                    this.controls.push(new OpenLayers.Control.ArgParser());
                }
                if (OpenLayers.Control.Attribution) {
                    this.controls.push(new OpenLayers.Control.Attribution());
                }
            }
        }

        for(var i=0, len=this.controls.length; i<len; i++) {
            this.addControlToMap(this.controls[i]);
        }

        this.popups = [];

        this.unloadDestroy = OpenLayers.Function.bind(this.destroy, this);
        

        // always call map.destroy()
        OpenLayers.Event.observe(window, 'unload', this.unloadDestroy);
        
        // add any initial layers
        if (options && options.layers) {
            /** 
             * If you have set options.center, the map center property will be
             * set at this point.  However, since setCenter has not been called,
             * addLayers gets confused.  So we delete the map center in this 
             * case.  Because the check below uses options.center, it will
             * be properly set below.
             */
            delete this.center;
            delete this.zoom;
            this.addLayers(options.layers);
            // set center (and optionally zoom)
            if (options.center && !this.getCenter()) {
                // zoom can be undefined here
                this.setCenter(options.center, options.zoom);
            }
        }

        if (this.panMethod) {
            this.panTween = new OpenLayers.Tween(this.panMethod);
        }
        if (this.zoomMethod && this.applyTransform.transform) {
            this.zoomTween = new OpenLayers.Tween(this.zoomMethod);
        }
    },

    /** 
     * APIMethod: getViewport
     * Get the DOMElement representing the view port.
     *
     * Returns:
     * {DOMElement}
     */
    getViewport: function() {
        return this.viewPortDiv;
    },
    
    /**
     * APIMethod: render
     * Render the map to a specified container.
     * 
     * Parameters:
     * div - {String|DOMElement} The container that the map should be rendered
     *     to. If different than the current container, the map viewport
     *     will be moved from the current to the new container.
     */
    render: function(div) {
        this.div = OpenLayers.Util.getElement(div);
        OpenLayers.Element.addClass(this.div, 'olMap');
        this.viewPortDiv.parentNode.removeChild(this.viewPortDiv);
        this.div.appendChild(this.viewPortDiv);
        this.updateSize();
    },

    /**
     * Method: unloadDestroy
     * Function that is called to destroy the map on page unload. stored here
     *     so that if map is manually destroyed, we can unregister this.
     */
    unloadDestroy: null,
    
    /**
     * Method: updateSizeDestroy
     * When the map is destroyed, we need to stop listening to updateSize
     *    events: this method stores the function we need to unregister in 
     *    non-IE browsers.
     */
    updateSizeDestroy: null,

    /**
     * APIMethod: destroy
     * Destroy this map.
     *    Note that if you are using an application which removes a container
     *    of the map from the DOM, you need to ensure that you destroy the
     *    map *before* this happens; otherwise, the page unload handler
     *    will fail because the DOM elements that map.destroy() wants
     *    to clean up will be gone. (See 
     *    http://trac.osgeo.org/openlayers/ticket/2277 for more information).
     *    This will apply to GeoExt and also to other applications which
     *    modify the DOM of the container of the OpenLayers Map.
     */
    destroy:function() {
        // if unloadDestroy is null, we've already been destroyed
        if (!this.unloadDestroy) {
            return false;
        }
        
        // make sure panning doesn't continue after destruction
        if(this.panTween) {
            this.panTween.stop();
            this.panTween = null;
        }
        // make sure zooming doesn't continue after destruction
        if(this.zoomTween) {
            this.zoomTween.stop();
            this.zoomTween = null;
        }

        // map has been destroyed. dont do it again!
        OpenLayers.Event.stopObserving(window, 'unload', this.unloadDestroy);
        this.unloadDestroy = null;

        if (this.updateSizeDestroy) {
            OpenLayers.Event.stopObserving(window, 'resize', 
                                           this.updateSizeDestroy);
        }
        
        this.paddingForPopups = null;    

        if (this.controls != null) {
            for (var i = this.controls.length - 1; i>=0; --i) {
                this.controls[i].destroy();
            } 
            this.controls = null;
        }
        if (this.layers != null) {
            for (var i = this.layers.length - 1; i>=0; --i) {
                //pass 'false' to destroy so that map wont try to set a new 
                // baselayer after each baselayer is removed
                this.layers[i].destroy(false);
            } 
            this.layers = null;
        }
        if (this.viewPortDiv && this.viewPortDiv.parentNode) {
            this.viewPortDiv.parentNode.removeChild(this.viewPortDiv);
        }
        this.viewPortDiv = null;
        
        if (this.tileManager) {
            this.tileManager.removeMap(this);
            this.tileManager = null;
        }

        if(this.eventListeners) {
            this.events.un(this.eventListeners);
            this.eventListeners = null;
        }
        this.events.destroy();
        this.events = null;

        this.options = null;
    },

    /**
     * APIMethod: setOptions
     * Change the map options
     *
     * Parameters:
     * options - {Object} Hashtable of options to tag to the map
     */
    setOptions: function(options) {
        var updatePxExtent = this.minPx &&
            options.restrictedExtent != this.restrictedExtent;
        OpenLayers.Util.extend(this, options);
        // force recalculation of minPx and maxPx
        updatePxExtent && this.moveTo(this.getCachedCenter(), this.zoom, {
            forceZoomChange: true
        });
    },

    /**
     * APIMethod: getTileSize
     * Get the tile size for the map
     *
     * Returns:
     * {<OpenLayers.Size>}
     */
     getTileSize: function() {
         return this.tileSize;
     },


    /**
     * APIMethod: getBy
     * Get a list of objects given a property and a match item.
     *
     * Parameters:
     * array - {String} A property on the map whose value is an array.
     * property - {String} A property on each item of the given array.
     * match - {String | Object} A string to match.  Can also be a regular
     *     expression literal or object.  In addition, it can be any object
     *     with a method named test.  For reqular expressions or other, if
     *     match.test(map[array][i][property]) evaluates to true, the item will
     *     be included in the array returned.  If no items are found, an empty
     *     array is returned.
     *
     * Returns:
     * {Array} An array of items where the given property matches the given
     *     criteria.
     */
    getBy: function(array, property, match) {
        var test = (typeof match.test == "function");
        var found = OpenLayers.Array.filter(this[array], function(item) {
            return item[property] == match || (test && match.test(item[property]));
        });
        return found;
    },

    /**
     * APIMethod: getLayersBy
     * Get a list of layers with properties matching the given criteria.
     *
     * Parameters:
     * property - {String} A layer property to be matched.
     * match - {String | Object} A string to match.  Can also be a regular
     *     expression literal or object.  In addition, it can be any object
     *     with a method named test.  For reqular expressions or other, if
     *     match.test(layer[property]) evaluates to true, the layer will be
     *     included in the array returned.  If no layers are found, an empty
     *     array is returned.
     *
     * Returns:
     * {Array(<OpenLayers.Layer>)} A list of layers matching the given criteria.
     *     An empty array is returned if no matches are found.
     */
    getLayersBy: function(property, match) {
        return this.getBy("layers", property, match);
    },

    /**
     * APIMethod: getLayersByName
     * Get a list of layers with names matching the given name.
     *
     * Parameters:
     * match - {String | Object} A layer name.  The name can also be a regular
     *     expression literal or object.  In addition, it can be any object
     *     with a method named test.  For reqular expressions or other, if
     *     name.test(layer.name) evaluates to true, the layer will be included
     *     in the list of layers returned.  If no layers are found, an empty
     *     array is returned.
     *
     * Returns:
     * {Array(<OpenLayers.Layer>)} A list of layers matching the given name.
     *     An empty array is returned if no matches are found.
     */
    getLayersByName: function(match) {
        return this.getLayersBy("name", match);
    },

    /**
     * APIMethod: getLayersByClass
     * Get a list of layers of a given class (CLASS_NAME).
     *
     * Parameters:
     * match - {String | Object} A layer class name.  The match can also be a
     *     regular expression literal or object.  In addition, it can be any
     *     object with a method named test.  For reqular expressions or other,
     *     if type.test(layer.CLASS_NAME) evaluates to true, the layer will
     *     be included in the list of layers returned.  If no layers are
     *     found, an empty array is returned.
     *
     * Returns:
     * {Array(<OpenLayers.Layer>)} A list of layers matching the given class.
     *     An empty array is returned if no matches are found.
     */
    getLayersByClass: function(match) {
        return this.getLayersBy("CLASS_NAME", match);
    },

    /**
     * APIMethod: getControlsBy
     * Get a list of controls with properties matching the given criteria.
     *
     * Parameters:
     * property - {String} A control property to be matched.
     * match - {String | Object} A string to match.  Can also be a regular
     *     expression literal or object.  In addition, it can be any object
     *     with a method named test.  For reqular expressions or other, if
     *     match.test(layer[property]) evaluates to true, the layer will be
     *     included in the array returned.  If no layers are found, an empty
     *     array is returned.
     *
     * Returns:
     * {Array(<OpenLayers.Control>)} A list of controls matching the given
     *     criteria.  An empty array is returned if no matches are found.
     */
    getControlsBy: function(property, match) {
        return this.getBy("controls", property, match);
    },

    /**
     * APIMethod: getControlsByClass
     * Get a list of controls of a given class (CLASS_NAME).
     *
     * Parameters:
     * match - {String | Object} A control class name.  The match can also be a
     *     regular expression literal or object.  In addition, it can be any
     *     object with a method named test.  For reqular expressions or other,
     *     if type.test(control.CLASS_NAME) evaluates to true, the control will
     *     be included in the list of controls returned.  If no controls are
     *     found, an empty array is returned.
     *
     * Returns:
     * {Array(<OpenLayers.Control>)} A list of controls matching the given class.
     *     An empty array is returned if no matches are found.
     */
    getControlsByClass: function(match) {
        return this.getControlsBy("CLASS_NAME", match);
    },

  /********************************************************/
  /*                                                      */
  /*                  Layer Functions                     */
  /*                                                      */
  /*     The following functions deal with adding and     */
  /*        removing Layers to and from the Map           */
  /*                                                      */
  /********************************************************/         

    /**
     * APIMethod: getLayer
     * Get a layer based on its id
     *
     * Parameters:
     * id - {String} A layer id
     *
     * Returns:
     * {<OpenLayers.Layer>} The Layer with the corresponding id from the map's 
     *                      layer collection, or null if not found.
     */
    getLayer: function(id) {
        var foundLayer = null;
        for (var i=0, len=this.layers.length; i<len; i++) {
            var layer = this.layers[i];
            if (layer.id == id) {
                foundLayer = layer;
                break;
            }
        }
        return foundLayer;
    },

    /**
    * Method: setLayerZIndex
    * 
    * Parameters:
    * layer - {<OpenLayers.Layer>} 
    * zIdx - {int} 
    */    
    setLayerZIndex: function (layer, zIdx) {
        layer.setZIndex(
            this.Z_INDEX_BASE[layer.isBaseLayer ? 'BaseLayer' : 'Overlay']
            + zIdx * 5 );
    },

    /**
     * Method: resetLayersZIndex
     * Reset each layer's z-index based on layer's array index
     */
    resetLayersZIndex: function() {
        for (var i=0, len=this.layers.length; i<len; i++) {
            var layer = this.layers[i];
            this.setLayerZIndex(layer, i);
        }
    },

    /**
    * APIMethod: addLayer
    *
    * Parameters:
    * layer - {<OpenLayers.Layer>} 
    *
    * Returns:
    * {Boolean} True if the layer has been added to the map.
    */    
    addLayer: function (layer) {
        for(var i = 0, len = this.layers.length; i < len; i++) {
            if (this.layers[i] == layer) {
                return false;
            }
        }
        if (this.events.triggerEvent("preaddlayer", {layer: layer}) === false) {
            return false;
        }
        if(this.allOverlays) {
            layer.isBaseLayer = false;
        }
        
        layer.div.className = "olLayerDiv";
        layer.div.style.overflow = "";
        this.setLayerZIndex(layer, this.layers.length);

        if (layer.isFixed) {
            this.viewPortDiv.appendChild(layer.div);
        } else {
            this.layerContainerDiv.appendChild(layer.div);
        }
        this.layers.push(layer);
        layer.setMap(this);

        if (layer.isBaseLayer || (this.allOverlays && !this.baseLayer))  {
            if (this.baseLayer == null) {
                // set the first baselaye we add as the baselayer
                this.setBaseLayer(layer);
            } else {
                layer.setVisibility(false);
            }
        } else {
            layer.redraw();
        }

        this.events.triggerEvent("addlayer", {layer: layer});
        layer.events.triggerEvent("added", {map: this, layer: layer});
        layer.afterAdd();

        return true;
    },

    /**
    * APIMethod: addLayers 
    *
    * Parameters:
    * layers - {Array(<OpenLayers.Layer>)} 
    */    
    addLayers: function (layers) {
        for (var i=0, len=layers.length; i<len; i++) {
            this.addLayer(layers[i]);
        }
    },

    /** 
     * APIMethod: removeLayer
     * Removes a layer from the map by removing its visual element (the 
     *   layer.div property), then removing it from the map's internal list 
     *   of layers, setting the layer's map property to null. 
     * 
     *   a "removelayer" event is triggered.
     * 
     *   very worthy of mention is that simply removing a layer from a map
     *   will not cause the removal of any popups which may have been created
     *   by the layer. this is due to the fact that it was decided at some
     *   point that popups would not belong to layers. thus there is no way 
     *   for us to know here to which layer the popup belongs.
     *    
     *     A simple solution to this is simply to call destroy() on the layer.
     *     the default OpenLayers.Layer class's destroy() function
     *     automatically takes care to remove itself from whatever map it has
     *     been attached to. 
     * 
     *     The correct solution is for the layer itself to register an 
     *     event-handler on "removelayer" and when it is called, if it 
     *     recognizes itself as the layer being removed, then it cycles through
     *     its own personal list of popups, removing them from the map.
     * 
     * Parameters:
     * layer - {<OpenLayers.Layer>} 
     * setNewBaseLayer - {Boolean} Default is true
     */
    removeLayer: function(layer, setNewBaseLayer) {
        if (this.events.triggerEvent("preremovelayer", {layer: layer}) === false) {
            return;
        }
        if (setNewBaseLayer == null) {
            setNewBaseLayer = true;
        }

        if (layer.isFixed) {
            this.viewPortDiv.removeChild(layer.div);
        } else {
            this.layerContainerDiv.removeChild(layer.div);
        }
        OpenLayers.Util.removeItem(this.layers, layer);
        layer.removeMap(this);
        layer.map = null;

        // if we removed the base layer, need to set a new one
        if(this.baseLayer == layer) {
            this.baseLayer = null;
            if(setNewBaseLayer) {
                for(var i=0, len=this.layers.length; i<len; i++) {
                    var iLayer = this.layers[i];
                    if (iLayer.isBaseLayer || this.allOverlays) {
                        this.setBaseLayer(iLayer);
                        break;
                    }
                }
            }
        }

        this.resetLayersZIndex();

        this.events.triggerEvent("removelayer", {layer: layer});
        layer.events.triggerEvent("removed", {map: this, layer: layer});
    },

    /**
     * APIMethod: getNumLayers
     * 
     * Returns:
     * {Int} The number of layers attached to the map.
     */
    getNumLayers: function () {
        return this.layers.length;
    },

    /** 
     * APIMethod: getLayerIndex
     *
     * Parameters:
     * layer - {<OpenLayers.Layer>}
     *
     * Returns:
     * {Integer} The current (zero-based) index of the given layer in the map's
     *           layer stack. Returns -1 if the layer isn't on the map.
     */
    getLayerIndex: function (layer) {
        return OpenLayers.Util.indexOf(this.layers, layer);
    },
    
    /** 
     * APIMethod: setLayerIndex
     * Move the given layer to the specified (zero-based) index in the layer
     *     list, changing its z-index in the map display. Use
     *     map.getLayerIndex() to find out the current index of a layer. Note
     *     that this cannot (or at least should not) be effectively used to
     *     raise base layers above overlays.
     *
     * Parameters:
     * layer - {<OpenLayers.Layer>} 
     * idx - {int} 
     */
    setLayerIndex: function (layer, idx) {
        var base = this.getLayerIndex(layer);
        if (idx < 0) {
            idx = 0;
        } else if (idx > this.layers.length) {
            idx = this.layers.length;
        }
        if (base != idx) {
            this.layers.splice(base, 1);
            this.layers.splice(idx, 0, layer);
            for (var i=0, len=this.layers.length; i<len; i++) {
                this.setLayerZIndex(this.layers[i], i);
            }
            this.events.triggerEvent("changelayer", {
                layer: layer, property: "order"
            });
            if(this.allOverlays) {
                if(idx === 0) {
                    this.setBaseLayer(layer);
                } else if(this.baseLayer !== this.layers[0]) {
                    this.setBaseLayer(this.layers[0]);
                }
            }
        }
    },

    /** 
     * APIMethod: raiseLayer
     * Change the index of the given layer by delta. If delta is positive, 
     *     the layer is moved up the map's layer stack; if delta is negative,
     *     the layer is moved down.  Again, note that this cannot (or at least
     *     should not) be effectively used to raise base layers above overlays.
     *
     * Paremeters:
     * layer - {<OpenLayers.Layer>} 
     * delta - {int} 
     */
    raiseLayer: function (layer, delta) {
        var idx = this.getLayerIndex(layer) + delta;
        this.setLayerIndex(layer, idx);
    },
    
    /** 
     * APIMethod: setBaseLayer
     * Allows user to specify one of the currently-loaded layers as the Map's
     *     new base layer.
     * 
     * Parameters:
     * newBaseLayer - {<OpenLayers.Layer>}
     */
    setBaseLayer: function(newBaseLayer) {
        
        if (newBaseLayer != this.baseLayer) {
          
            // ensure newBaseLayer is already loaded
            if (OpenLayers.Util.indexOf(this.layers, newBaseLayer) != -1) {

                // preserve center and scale when changing base layers
                var center = this.getCachedCenter();
                var newResolution = OpenLayers.Util.getResolutionFromScale(
                    this.getScale(), newBaseLayer.units
                );

                // make the old base layer invisible 
                if (this.baseLayer != null && !this.allOverlays) {
                    this.baseLayer.setVisibility(false);
                }

                // set new baselayer
                this.baseLayer = newBaseLayer;
                
                if(!this.allOverlays || this.baseLayer.visibility) {
                    this.baseLayer.setVisibility(true);
                    // Layer may previously have been visible but not in range.
                    // In this case we need to redraw it to make it visible.
                    if (this.baseLayer.inRange === false) {
                        this.baseLayer.redraw();
                    }
                }

                // recenter the map
                if (center != null) {
                    // new zoom level derived from old scale
                    var newZoom = this.getZoomForResolution(
                        newResolution || this.resolution, true
                    );
                    // zoom and force zoom change
                    this.setCenter(center, newZoom, false, true);
                }

                this.events.triggerEvent("changebaselayer", {
                    layer: this.baseLayer
                });
            }        
        }
    },


  /********************************************************/
  /*                                                      */
  /*                 Control Functions                    */
  /*                                                      */
  /*     The following functions deal with adding and     */
  /*        removing Controls to and from the Map         */
  /*                                                      */
  /********************************************************/         

    /**
     * APIMethod: addControl
     * Add the passed over control to the map. Optionally 
     *     position the control at the given pixel.
     * 
     * Parameters:
     * control - {<OpenLayers.Control>}
     * px - {<OpenLayers.Pixel>}
     */    
    addControl: function (control, px) {
        this.controls.push(control);
        this.addControlToMap(control, px);
    },
    
    /**
     * APIMethod: addControls
     * Add all of the passed over controls to the map. 
     *     You can pass over an optional second array
     *     with pixel-objects to position the controls.
     *     The indices of the two arrays should match and
     *     you can add null as pixel for those controls 
     *     you want to be autopositioned.   
     *     
     * Parameters:
     * controls - {Array(<OpenLayers.Control>)}
     * pixels - {Array(<OpenLayers.Pixel>)}
     */    
    addControls: function (controls, pixels) {
        var pxs = (arguments.length === 1) ? [] : pixels;
        for (var i=0, len=controls.length; i<len; i++) {
            var ctrl = controls[i];
            var px = (pxs[i]) ? pxs[i] : null;
            this.addControl( ctrl, px );
        }
    },

    /**
     * Method: addControlToMap
     * 
     * Parameters:
     * 
     * control - {<OpenLayers.Control>}
     * px - {<OpenLayers.Pixel>}
     */    
    addControlToMap: function (control, px) {
        // If a control doesn't have a div at this point, it belongs in the
        // viewport.
        control.outsideViewport = (control.div != null);
        
        // If the map has a displayProjection, and the control doesn't, set 
        // the display projection.
        if (this.displayProjection && !control.displayProjection) {
            control.displayProjection = this.displayProjection;
        }    
        
        control.setMap(this);
        var div = control.draw(px);
        if (div) {
            if(!control.outsideViewport) {
                div.style.zIndex = this.Z_INDEX_BASE['Control'] +
                                    this.controls.length;
                this.viewPortDiv.appendChild( div );
            }
        }
        if(control.autoActivate) {
            control.activate();
        }
    },
    
    /**
     * APIMethod: getControl
     * 
     * Parameters:
     * id - {String} ID of the control to return.
     * 
     * Returns:
     * {<OpenLayers.Control>} The control from the map's list of controls 
     *                        which has a matching 'id'. If none found, 
     *                        returns null.
     */    
    getControl: function (id) {
        var returnControl = null;
        for(var i=0, len=this.controls.length; i<len; i++) {
            var control = this.controls[i];
            if (control.id == id) {
                returnControl = control;
                break;
            }
        }
        return returnControl;
    },
    
    /** 
     * APIMethod: removeControl
     * Remove a control from the map. Removes the control both from the map 
     *     object's internal array of controls, as well as from the map's 
     *     viewPort (assuming the control was not added outsideViewport)
     * 
     * Parameters:
     * control - {<OpenLayers.Control>} The control to remove.
     */    
    removeControl: function (control) {
        //make sure control is non-null and actually part of our map
        if ( (control) && (control == this.getControl(control.id)) ) {
            if (control.div && (control.div.parentNode == this.viewPortDiv)) {
                this.viewPortDiv.removeChild(control.div);
            }
            OpenLayers.Util.removeItem(this.controls, control);
        }
    },

  /********************************************************/
  /*                                                      */
  /*                  Popup Functions                     */
  /*                                                      */
  /*     The following functions deal with adding and     */
  /*        removing Popups to and from the Map           */
  /*                                                      */
  /********************************************************/         

    /** 
     * APIMethod: addPopup
     * 
     * Parameters:
     * popup - {<OpenLayers.Popup>}
     * exclusive - {Boolean} If true, closes all other popups first
     */
    addPopup: function(popup, exclusive) {

        if (exclusive) {
            //remove all other popups from screen
            for (var i = this.popups.length - 1; i >= 0; --i) {
                this.removePopup(this.popups[i]);
            }
        }

        popup.map = this;
        this.popups.push(popup);
        var popupDiv = popup.draw();
        if (popupDiv) {
            popupDiv.style.zIndex = this.Z_INDEX_BASE['Popup'] +
                                    this.popups.length;
            this.layerContainerDiv.appendChild(popupDiv);
        }
    },
    
    /** 
    * APIMethod: removePopup
    * 
    * Parameters:
    * popup - {<OpenLayers.Popup>}
    */
    removePopup: function(popup) {
        OpenLayers.Util.removeItem(this.popups, popup);
        if (popup.div) {
            try { this.layerContainerDiv.removeChild(popup.div); }
            catch (e) { } // Popups sometimes apparently get disconnected
                      // from the layerContainerDiv, and cause complaints.
        }
        popup.map = null;
    },

  /********************************************************/
  /*                                                      */
  /*              Container Div Functions                 */
  /*                                                      */
  /*   The following functions deal with the access to    */
  /*    and maintenance of the size of the container div  */
  /*                                                      */
  /********************************************************/     

    /**
     * APIMethod: getSize
     * 
     * Returns:
     * {<OpenLayers.Size>} An <OpenLayers.Size> object that represents the 
     *                     size, in pixels, of the div into which OpenLayers 
     *                     has been loaded. 
     *                     Note - A clone() of this locally cached variable is
     *                     returned, so as not to allow users to modify it.
     */
    getSize: function () {
        var size = null;
        if (this.size != null) {
            size = this.size.clone();
        }
        return size;
    },

    /**
     * APIMethod: updateSize
     * This function should be called by any external code which dynamically
     *     changes the size of the map div (because mozilla wont let us catch 
     *     the "onresize" for an element)
     */
    updateSize: function() {
        // the div might have moved on the page, also
        var newSize = this.getCurrentSize();
        if (newSize && !isNaN(newSize.h) && !isNaN(newSize.w)) {
            this.events.clearMouseCache();
            var oldSize = this.getSize();
            if (oldSize == null) {
                this.size = oldSize = newSize;
            }
            if (!newSize.equals(oldSize)) {
                
                // store the new size
                this.size = newSize;
    
                //notify layers of mapresize
                for(var i=0, len=this.layers.length; i<len; i++) {
                    this.layers[i].onMapResize();                
                }
    
                var center = this.getCachedCenter();
    
                if (this.baseLayer != null && center != null) {
                    var zoom = this.getZoom();
                    this.zoom = null;
                    this.setCenter(center, zoom);
                }
    
            }
        }
        this.events.triggerEvent("updatesize");
    },
    
    /**
     * Method: getCurrentSize
     * 
     * Returns:
     * {<OpenLayers.Size>} A new <OpenLayers.Size> object with the dimensions 
     *                     of the map div
     */
    getCurrentSize: function() {

        var size = new OpenLayers.Size(this.div.clientWidth, 
                                       this.div.clientHeight);

        if (size.w == 0 && size.h == 0 || isNaN(size.w) && isNaN(size.h)) {
            size.w = this.div.offsetWidth;
            size.h = this.div.offsetHeight;
        }
        if (size.w == 0 && size.h == 0 || isNaN(size.w) && isNaN(size.h)) {
            size.w = parseInt(this.div.style.width);
            size.h = parseInt(this.div.style.height);
        }
        return size;
    },

    /** 
     * Method: calculateBounds
     * 
     * Parameters:
     * center - {<OpenLayers.LonLat>} Default is this.getCenter()
     * resolution - {float} Default is this.getResolution() 
     * 
     * Returns:
     * {<OpenLayers.Bounds>} A bounds based on resolution, center, and 
     *                       current mapsize.
     */
    calculateBounds: function(center, resolution) {

        var extent = null;
        
        if (center == null) {
            center = this.getCachedCenter();
        }                
        if (resolution == null) {
            resolution = this.getResolution();
        }
    
        if ((center != null) && (resolution != null)) {
            var halfWDeg = (this.size.w * resolution) / 2;
            var halfHDeg = (this.size.h * resolution) / 2;
        
            extent = new OpenLayers.Bounds(center.lon - halfWDeg,
                                           center.lat - halfHDeg,
                                           center.lon + halfWDeg,
                                           center.lat + halfHDeg);
        }

        return extent;
    },


  /********************************************************/
  /*                                                      */
  /*            Zoom, Center, Pan Functions               */
  /*                                                      */
  /*    The following functions handle the validation,    */
  /*   getting and setting of the Zoom Level and Center   */
  /*       as well as the panning of the Map              */
  /*                                                      */
  /********************************************************/
    /**
     * APIMethod: getCenter
     * 
     * Returns:
     * {<OpenLayers.LonLat>}
     */
    getCenter: function () {
        var center = null;
        var cachedCenter = this.getCachedCenter();
        if (cachedCenter) {
            center = cachedCenter.clone();
        }
        return center;
    },

    /**
     * Method: getCachedCenter
     *
     * Returns:
     * {<OpenLayers.LonLat>}
     */
    getCachedCenter: function() {
        if (!this.center && this.size) {
            this.center = this.getLonLatFromViewPortPx({
                x: this.size.w / 2,
                y: this.size.h / 2
            });
        }
        return this.center;
    },

    /**
     * APIMethod: getZoom
     * 
     * Returns:
     * {Integer}
     */
    getZoom: function () {
        return this.zoom;
    },
    
    /** 
     * APIMethod: pan
     * Allows user to pan by a value of screen pixels
     * 
     * Parameters:
     * dx - {Integer}
     * dy - {Integer}
     * options - {Object} Options to configure panning:
     *  - *animate* {Boolean} Use panTo instead of setCenter. Default is true.
     *  - *dragging* {Boolean} Call setCenter with dragging true.  Default is
     *    false.
     */
    pan: function(dx, dy, options) {
        options = OpenLayers.Util.applyDefaults(options, {
            animate: true,
            dragging: false
        });
        if (options.dragging) {
            if (dx != 0 || dy != 0) {
                this.moveByPx(dx, dy);
            }
        } else {
            // getCenter
            var centerPx = this.getViewPortPxFromLonLat(this.getCachedCenter());

            // adjust
            var newCenterPx = centerPx.add(dx, dy);

            if (this.dragging || !newCenterPx.equals(centerPx)) {
                var newCenterLonLat = this.getLonLatFromViewPortPx(newCenterPx);
                if (options.animate) {
                    this.panTo(newCenterLonLat);
                } else {
                    this.moveTo(newCenterLonLat);
                    if(this.dragging) {
                        this.dragging = false;
                        this.events.triggerEvent("moveend");
                    }
                }    
            }
        }        

   },
   
   /** 
     * APIMethod: panTo
     * Allows user to pan to a new lonlat
     * If the new lonlat is in the current extent the map will slide smoothly
     * 
     * Parameters:
     * lonlat - {<OpenLayers.LonLat>}
     */
    panTo: function(lonlat) {
        if (this.panTween && this.getExtent().scale(this.panRatio).containsLonLat(lonlat)) {
            var center = this.getCachedCenter();

            // center will not change, don't do nothing
            if (lonlat.equals(center)) {
                return;
            }

            var from = this.getPixelFromLonLat(center);
            var to = this.getPixelFromLonLat(lonlat);
            var vector = { x: to.x - from.x, y: to.y - from.y };
            var last = { x: 0, y: 0 };

            this.panTween.start( { x: 0, y: 0 }, vector, this.panDuration, {
                callbacks: {
                    eachStep: OpenLayers.Function.bind(function(px) {
                        var x = px.x - last.x,
                            y = px.y - last.y;
                        this.moveByPx(x, y);
                        last.x = Math.round(px.x);
                        last.y = Math.round(px.y);
                    }, this),
                    done: OpenLayers.Function.bind(function(px) {
                        this.moveTo(lonlat);
                        this.dragging = false;
                        this.events.triggerEvent("moveend");
                    }, this)
                }
            });
        } else {
            this.setCenter(lonlat);
        }
    },

    /**
     * APIMethod: setCenter
     * Set the map center (and optionally, the zoom level).
     * 
     * Parameters:
     * lonlat - {<OpenLayers.LonLat>|Array} The new center location.
     *     If provided as array, the first value is the x coordinate,
     *     and the 2nd value is the y coordinate.
     * zoom - {Integer} Optional zoom level.
     * dragging - {Boolean} Specifies whether or not to trigger 
     *                      movestart/end events
     * forceZoomChange - {Boolean} Specifies whether or not to trigger zoom 
     *                             change events (needed on baseLayer change)
     *
     * TBD: reconsider forceZoomChange in 3.0
     */
    setCenter: function(lonlat, zoom, dragging, forceZoomChange) {
        if (this.panTween) {
            this.panTween.stop();
        }
        if (this.zoomTween) {
            this.zoomTween.stop();
        }            
        this.moveTo(lonlat, zoom, {
            'dragging': dragging,
            'forceZoomChange': forceZoomChange
        });
    },
    
    /** 
     * Method: moveByPx
     * Drag the map by pixels.
     *
     * Parameters:
     * dx - {Number}
     * dy - {Number}
     */
    moveByPx: function(dx, dy) {
        var hw = this.size.w / 2;
        var hh = this.size.h / 2;
        var x = hw + dx;
        var y = hh + dy;
        var wrapDateLine = this.baseLayer.wrapDateLine;
        var xRestriction = 0;
        var yRestriction = 0;
        if (this.restrictedExtent) {
            xRestriction = hw;
            yRestriction = hh;
            // wrapping the date line makes no sense for restricted extents
            wrapDateLine = false;
        }
        dx = wrapDateLine ||
                    x <= this.maxPx.x - xRestriction &&
                    x >= this.minPx.x + xRestriction ? Math.round(dx) : 0;
        dy = y <= this.maxPx.y - yRestriction &&
                    y >= this.minPx.y + yRestriction ? Math.round(dy) : 0;
        if (dx || dy) {
            if (!this.dragging) {
                this.dragging = true;
                this.events.triggerEvent("movestart");
            }
            this.center = null;
            if (dx) {
                this.layerContainerOriginPx.x -= dx;
                this.minPx.x -= dx;
                this.maxPx.x -= dx;
            }
            if (dy) {
                this.layerContainerOriginPx.y -= dy;
                this.minPx.y -= dy;
                this.maxPx.y -= dy;
            }
            this.applyTransform();
            var layer, i, len;
            for (i=0, len=this.layers.length; i<len; ++i) {
                layer = this.layers[i];
                if (layer.visibility &&
                    (layer === this.baseLayer || layer.inRange)) {
                    layer.moveByPx(dx, dy);
                    layer.events.triggerEvent("move");
                }
            }
            this.events.triggerEvent("move");
        }
    },
    
    /**
     * Method: adjustZoom
     *
     * Parameters:
     * zoom - {Number} The zoom level to adjust
     *
     * Returns:
     * {Integer} Adjusted zoom level that shows a map not wider than its
     * <baseLayer>'s maxExtent.
     */
    adjustZoom: function(zoom) {
        if (this.baseLayer && this.baseLayer.wrapDateLine) {
            var resolution, resolutions = this.baseLayer.resolutions,
                maxResolution = this.getMaxExtent().getWidth() / this.size.w;
            if (this.getResolutionForZoom(zoom) > maxResolution) {
                if (this.fractionalZoom) {
                    zoom = this.getZoomForResolution(maxResolution);
                } else {
                    for (var i=zoom|0, ii=resolutions.length; i<ii; ++i) {
                        if (resolutions[i] <= maxResolution) {
                            zoom = i;
                            break;
                        }
                    }
                } 
            }
        }
        return zoom;
    },
    
    /**
     * APIMethod: getMinZoom
     * Returns the minimum zoom level for the current map view. If the base
     * layer is configured with <wrapDateLine> set to true, this will be the
     * first zoom level that shows no more than one world width in the current
     * map viewport. Components that rely on this value (e.g. zoom sliders)
     * should also listen to the map's "updatesize" event and call this method
     * in the "updatesize" listener.
     *
     * Returns:
     * {Number} Minimum zoom level that shows a map not wider than its
     * <baseLayer>'s maxExtent. This is an Integer value, unless the map is
     * configured with <fractionalZoom> set to true.
     */
    getMinZoom: function() {
        return this.adjustZoom(0);
    },

    /**
     * Method: moveTo
     *
     * Parameters:
     * lonlat - {<OpenLayers.LonLat>}
     * zoom - {Integer}
     * options - {Object}
     */
    moveTo: function(lonlat, zoom, options) {
        if (lonlat != null && !(lonlat instanceof OpenLayers.LonLat)) {
            lonlat = new OpenLayers.LonLat(lonlat);
        }
        if (!options) { 
            options = {};
        }
        if (zoom != null) {
            zoom = parseFloat(zoom);
            if (!this.fractionalZoom) {
                zoom = Math.round(zoom);
            }
        }
        var requestedZoom = zoom;
        zoom = this.adjustZoom(zoom);
        if (zoom !== requestedZoom) {
            // zoom was adjusted, so keep old lonlat to avoid panning
            lonlat = this.getCenter();
        }
        // dragging is false by default
        var dragging = options.dragging || this.dragging;
        // forceZoomChange is false by default
        var forceZoomChange = options.forceZoomChange;

        if (!this.getCachedCenter() && !this.isValidLonLat(lonlat)) {
            lonlat = this.maxExtent.getCenterLonLat();
            this.center = lonlat.clone();
        }

        if(this.restrictedExtent != null) {
            // In 3.0, decide if we want to change interpretation of maxExtent.
            if(lonlat == null) { 
                lonlat = this.center; 
            }
            if(zoom == null) { 
                zoom = this.getZoom(); 
            }
            var resolution = this.getResolutionForZoom(zoom);
            var extent = this.calculateBounds(lonlat, resolution); 
            if(!this.restrictedExtent.containsBounds(extent)) {
                var maxCenter = this.restrictedExtent.getCenterLonLat(); 
                if(extent.getWidth() > this.restrictedExtent.getWidth()) { 
                    lonlat = new OpenLayers.LonLat(maxCenter.lon, lonlat.lat); 
                } else if(extent.left < this.restrictedExtent.left) {
                    lonlat = lonlat.add(this.restrictedExtent.left -
                                        extent.left, 0); 
                } else if(extent.right > this.restrictedExtent.right) { 
                    lonlat = lonlat.add(this.restrictedExtent.right -
                                        extent.right, 0); 
                } 
                if(extent.getHeight() > this.restrictedExtent.getHeight()) { 
                    lonlat = new OpenLayers.LonLat(lonlat.lon, maxCenter.lat); 
                } else if(extent.bottom < this.restrictedExtent.bottom) { 
                    lonlat = lonlat.add(0, this.restrictedExtent.bottom -
                                        extent.bottom); 
                } 
                else if(extent.top > this.restrictedExtent.top) { 
                    lonlat = lonlat.add(0, this.restrictedExtent.top -
                                        extent.top); 
                } 
            }
        }
        
        var zoomChanged = forceZoomChange || (
                            (this.isValidZoomLevel(zoom)) && 
                            (zoom != this.getZoom()) );

        var centerChanged = (this.isValidLonLat(lonlat)) && 
                            (!lonlat.equals(this.center));

        // if neither center nor zoom will change, no need to do anything
        if (zoomChanged || centerChanged || dragging) {
            dragging || this.events.triggerEvent("movestart", {
                zoomChanged: zoomChanged
            });

            if (centerChanged) {
                if (!zoomChanged && this.center) { 
                    // if zoom hasnt changed, just slide layerContainer
                    //  (must be done before setting this.center to new value)
                    this.centerLayerContainer(lonlat);
                }
                this.center = lonlat.clone();
            }

            var res = zoomChanged ?
                this.getResolutionForZoom(zoom) : this.getResolution();
            // (re)set the layerContainerDiv's location
            if (zoomChanged || this.layerContainerOrigin == null) {
                this.layerContainerOrigin = this.getCachedCenter();
                this.layerContainerOriginPx.x = 0;
                this.layerContainerOriginPx.y = 0;
                this.applyTransform();
                var maxExtent = this.getMaxExtent({restricted: true});
                var maxExtentCenter = maxExtent.getCenterLonLat();
                var lonDelta = this.center.lon - maxExtentCenter.lon;
                var latDelta = maxExtentCenter.lat - this.center.lat;
                var extentWidth = Math.round(maxExtent.getWidth() / res);
                var extentHeight = Math.round(maxExtent.getHeight() / res);
                this.minPx = {
                    x: (this.size.w - extentWidth) / 2 - lonDelta / res,
                    y: (this.size.h - extentHeight) / 2 - latDelta / res
                };
                this.maxPx = {
                    x: this.minPx.x + Math.round(maxExtent.getWidth() / res),
                    y: this.minPx.y + Math.round(maxExtent.getHeight() / res)
                };
            }

            if (zoomChanged) {
                this.zoom = zoom;
                this.resolution = res;
            }    
            
            var bounds = this.getExtent();
            
            //send the move call to the baselayer and all the overlays    

            if(this.baseLayer.visibility) {
                this.baseLayer.moveTo(bounds, zoomChanged, options.dragging);
                options.dragging || this.baseLayer.events.triggerEvent(
                    "moveend", {zoomChanged: zoomChanged}
                );
            }
            
            bounds = this.baseLayer.getExtent();
            
            for (var i=this.layers.length-1; i>=0; --i) {
                var layer = this.layers[i];
                if (layer !== this.baseLayer && !layer.isBaseLayer) {
                    var inRange = layer.calculateInRange();
                    if (layer.inRange != inRange) {
                        // the inRange property has changed. If the layer is
                        // no longer in range, we turn it off right away. If
                        // the layer is no longer out of range, the moveTo
                        // call below will turn on the layer.
                        layer.inRange = inRange;
                        if (!inRange) {
                            layer.display(false);
                        }
                        this.events.triggerEvent("changelayer", {
                            layer: layer, property: "visibility"
                        });
                    }
                    if (inRange && layer.visibility) {
                        layer.moveTo(bounds, zoomChanged, options.dragging);
                        options.dragging || layer.events.triggerEvent(
                            "moveend", {zoomChanged: zoomChanged}
                        );
                    }
                }                
            }
            
            this.events.triggerEvent("move");
            dragging || this.events.triggerEvent("moveend");

            if (zoomChanged) {
                //redraw popups
                for (var i=0, len=this.popups.length; i<len; i++) {
                    this.popups[i].updatePosition();
                }
                this.events.triggerEvent("zoomend");
            }
        }
    },

    /** 
     * Method: centerLayerContainer
     * This function takes care to recenter the layerContainerDiv.
     * 
     * Parameters:
     * lonlat - {<OpenLayers.LonLat>}
     */
    centerLayerContainer: function (lonlat) {
        var originPx = this.getViewPortPxFromLonLat(this.layerContainerOrigin);
        var newPx = this.getViewPortPxFromLonLat(lonlat);

        if ((originPx != null) && (newPx != null)) {
            var oldLeft = this.layerContainerOriginPx.x;
            var oldTop = this.layerContainerOriginPx.y;
            var newLeft = Math.round(originPx.x - newPx.x);
            var newTop = Math.round(originPx.y - newPx.y);
            this.applyTransform(
                (this.layerContainerOriginPx.x = newLeft),
                (this.layerContainerOriginPx.y = newTop));
            var dx = oldLeft - newLeft;
            var dy = oldTop - newTop;
            this.minPx.x -= dx;
            this.maxPx.x -= dx;
            this.minPx.y -= dy;
            this.maxPx.y -= dy;
        }        
    },

    /**
     * Method: isValidZoomLevel
     * 
     * Parameters:
     * zoomLevel - {Integer}
     * 
     * Returns:
     * {Boolean} Whether or not the zoom level passed in is non-null and 
     *           within the min/max range of zoom levels.
     */
    isValidZoomLevel: function(zoomLevel) {
        return ( (zoomLevel != null) &&
                 (zoomLevel >= 0) && 
                 (zoomLevel < this.getNumZoomLevels()) );
    },
    
    /**
     * Method: isValidLonLat
     * 
     * Parameters:
     * lonlat - {<OpenLayers.LonLat>}
     * 
     * Returns:
     * {Boolean} Whether or not the lonlat passed in is non-null and within
     *           the maxExtent bounds
     */
    isValidLonLat: function(lonlat) {
        var valid = false;
        if (lonlat != null) {
            var maxExtent = this.getMaxExtent();
            var worldBounds = this.baseLayer.wrapDateLine && maxExtent;
            valid = maxExtent.containsLonLat(lonlat, {worldBounds: worldBounds});
        }
        return valid;
    },

  /********************************************************/
  /*                                                      */
  /*                 Layer Options                        */
  /*                                                      */
  /*    Accessor functions to Layer Options parameters    */
  /*                                                      */
  /********************************************************/
    
    /**
     * APIMethod: getProjection
     * This method returns a string representing the projection. In 
     *     the case of projection support, this will be the srsCode which
     *     is loaded -- otherwise it will simply be the string value that
     *     was passed to the projection at startup.
     *
     * FIXME: In 3.0, we will remove getProjectionObject, and instead
     *     return a Projection object from this function. 
     * 
     * Returns:
     * {String} The Projection string from the base layer or null. 
     */
    getProjection: function() {
        var projection = this.getProjectionObject();
        return projection ? projection.getCode() : null;
    },
    
    /**
     * APIMethod: getProjectionObject
     * Returns the projection obect from the baselayer.
     *
     * Returns:
     * {<OpenLayers.Projection>} The Projection of the base layer.
     */
    getProjectionObject: function() {
        var projection = null;
        if (this.baseLayer != null) {
            projection = this.baseLayer.projection;
        }
        return projection;
    },
    
    /**
     * APIMethod: getMaxResolution
     * 
     * Returns:
     * {String} The Map's Maximum Resolution
     */
    getMaxResolution: function() {
        var maxResolution = null;
        if (this.baseLayer != null) {
            maxResolution = this.baseLayer.maxResolution;
        }
        return maxResolution;
    },
        
    /**
     * APIMethod: getMaxExtent
     *
     * Parameters:
     * options - {Object} 
     * 
     * Allowed Options:
     * restricted - {Boolean} If true, returns restricted extent (if it is 
     *     available.)
     *
     * Returns:
     * {<OpenLayers.Bounds>} The maxExtent property as set on the current 
     *     baselayer, unless the 'restricted' option is set, in which case
     *     the 'restrictedExtent' option from the map is returned (if it
     *     is set).
     */
    getMaxExtent: function (options) {
        var maxExtent = null;
        if(options && options.restricted && this.restrictedExtent){
            maxExtent = this.restrictedExtent;
        } else if (this.baseLayer != null) {
            maxExtent = this.baseLayer.maxExtent;
        }        
        return maxExtent;
    },
    
    /**
     * APIMethod: getNumZoomLevels
     * 
     * Returns:
     * {Integer} The total number of zoom levels that can be displayed by the 
     *           current baseLayer.
     */
    getNumZoomLevels: function() {
        var numZoomLevels = null;
        if (this.baseLayer != null) {
            numZoomLevels = this.baseLayer.numZoomLevels;
        }
        return numZoomLevels;
    },

  /********************************************************/
  /*                                                      */
  /*                 Baselayer Functions                  */
  /*                                                      */
  /*    The following functions, all publicly exposed     */
  /*       in the API?, are all merely wrappers to the    */
  /*       the same calls on whatever layer is set as     */
  /*                the current base layer                */
  /*                                                      */
  /********************************************************/

    /**
     * APIMethod: getExtent
     * 
     * Returns:
     * {<OpenLayers.Bounds>} A Bounds object which represents the lon/lat 
     *                       bounds of the current viewPort. 
     *                       If no baselayer is set, returns null.
     */
    getExtent: function () {
        var extent = null;
        if (this.baseLayer != null) {
            extent = this.baseLayer.getExtent();
        }
        return extent;
    },

    /**
     * APIMethod: getResolution
     * 
     * Returns:
     * {Float} The current resolution of the map. 
     *         If no baselayer is set, returns null.
     */
    getResolution: function () {
        var resolution = null;
        if (this.baseLayer != null) {
            resolution = this.baseLayer.getResolution();
        } else if(this.allOverlays === true && this.layers.length > 0) {
            // while adding the 1st layer to the map in allOverlays mode,
            // this.baseLayer is not set yet when we need the resolution
            // for calculateInRange.
            resolution = this.layers[0].getResolution();
        }
        return resolution;
    },

    /**
     * APIMethod: getUnits
     * 
     * Returns:
     * {Float} The current units of the map. 
     *         If no baselayer is set, returns null.
     */
    getUnits: function () {
        var units = null;
        if (this.baseLayer != null) {
            units = this.baseLayer.units;
        }
        return units;
    },

     /**
      * APIMethod: getScale
      * 
      * Returns:
      * {Float} The current scale denominator of the map. 
      *         If no baselayer is set, returns null.
      */
    getScale: function () {
        var scale = null;
        if (this.baseLayer != null) {
            var res = this.getResolution();
            var units = this.baseLayer.units;
            scale = OpenLayers.Util.getScaleFromResolution(res, units);
        }
        return scale;
    },


    /**
     * APIMethod: getZoomForExtent
     * 
     * Parameters: 
     * bounds - {<OpenLayers.Bounds>}
     * closest - {Boolean} Find the zoom level that most closely fits the 
     *     specified bounds. Note that this may result in a zoom that does 
     *     not exactly contain the entire extent.
     *     Default is false.
     * 
     * Returns:
     * {Integer} A suitable zoom level for the specified bounds.
     *           If no baselayer is set, returns null.
     */
    getZoomForExtent: function (bounds, closest) {
        var zoom = null;
        if (this.baseLayer != null) {
            zoom = this.baseLayer.getZoomForExtent(bounds, closest);
        }
        return zoom;
    },

    /**
     * APIMethod: getResolutionForZoom
     * 
     * Parameters:
     * zoom - {Float}
     * 
     * Returns:
     * {Float} A suitable resolution for the specified zoom.  If no baselayer
     *     is set, returns null.
     */
    getResolutionForZoom: function(zoom) {
        var resolution = null;
        if(this.baseLayer) {
            resolution = this.baseLayer.getResolutionForZoom(zoom);
        }
        return resolution;
    },

    /**
     * APIMethod: getZoomForResolution
     * 
     * Parameters:
     * resolution - {Float}
     * closest - {Boolean} Find the zoom level that corresponds to the absolute 
     *     closest resolution, which may result in a zoom whose corresponding
     *     resolution is actually smaller than we would have desired (if this
     *     is being called from a getZoomForExtent() call, then this means that
     *     the returned zoom index might not actually contain the entire 
     *     extent specified... but it'll be close).
     *     Default is false.
     * 
     * Returns:
     * {Integer} A suitable zoom level for the specified resolution.
     *           If no baselayer is set, returns null.
     */
    getZoomForResolution: function(resolution, closest) {
        var zoom = null;
        if (this.baseLayer != null) {
            zoom = this.baseLayer.getZoomForResolution(resolution, closest);
        }
        return zoom;
    },

  /********************************************************/
  /*                                                      */
  /*                  Zooming Functions                   */
  /*                                                      */
  /*    The following functions, all publicly exposed     */
  /*       in the API, are all merely wrappers to the     */
  /*               the setCenter() function               */
  /*                                                      */
  /********************************************************/
  
    /** 
     * APIMethod: zoomTo
     * Zoom to a specific zoom level. Zooming will be animated unless the map
     * is configured with {zoomMethod: null}. To zoom without animation, use
     * <setCenter> without a lonlat argument.
     * 
     * Parameters:
     * zoom - {Integer}
     */
    zoomTo: function(zoom, xy) {
        // non-API arguments:
        // xy - {<OpenLayers.Pixel>} optional zoom origin
        
        var map = this;
        if (map.isValidZoomLevel(zoom)) {
            if (map.baseLayer.wrapDateLine) {
                zoom = map.adjustZoom(zoom);
            }
            if (map.zoomTween) {
                var currentRes = map.getResolution(),
                    targetRes = map.getResolutionForZoom(zoom),
                    start = {scale: 1},
                    end = {scale: currentRes / targetRes};
                if (map.zoomTween.playing && map.zoomTween.duration < 3 * map.zoomDuration) {
                    // update the end scale, and reuse the running zoomTween
                    map.zoomTween.finish = {
                        scale: map.zoomTween.finish.scale * end.scale
                    };
                } else {
                    if (!xy) {
                        var size = map.getSize();
                        xy = {x: size.w / 2, y: size.h / 2};
                    }
                    map.zoomTween.start(start, end, map.zoomDuration, {
                        minFrameRate: 50, // don't spend much time zooming
                        callbacks: {
                            eachStep: function(data) {
                                var containerOrigin = map.layerContainerOriginPx,
                                    scale = data.scale,
                                    dx = ((scale - 1) * (containerOrigin.x - xy.x)) | 0,
                                    dy = ((scale - 1) * (containerOrigin.y - xy.y)) | 0;
                                map.applyTransform(containerOrigin.x + dx, containerOrigin.y + dy, scale);
                            },
                            done: function(data) {
                                map.applyTransform();
                                var resolution = map.getResolution() / data.scale,
                                    zoom = map.getZoomForResolution(resolution, true)
                                map.moveTo(map.getZoomTargetCenter(xy, resolution), zoom, true);
                            }
                        }
                    });
                }
            } else {
                var center = xy ?
                    map.getZoomTargetCenter(xy, map.getResolutionForZoom(zoom)) :
                    null;
                map.setCenter(center, zoom);
            }
        }
    },
        
    /**
     * APIMethod: zoomIn
     * 
     */
    zoomIn: function() {
        this.zoomTo(this.getZoom() + 1);
    },
    
    /**
     * APIMethod: zoomOut
     * 
     */
    zoomOut: function() {
        this.zoomTo(this.getZoom() - 1);
    },

    /**
     * APIMethod: zoomToExtent
     * Zoom to the passed in bounds, recenter
     * 
     * Parameters:
     * bounds - {<OpenLayers.Bounds>|Array} If provided as an array, the array
     *     should consist of four values (left, bottom, right, top).
     * closest - {Boolean} Find the zoom level that most closely fits the 
     *     specified bounds. Note that this may result in a zoom that does 
     *     not exactly contain the entire extent.
     *     Default is false.
     * 
     */
    zoomToExtent: function(bounds, closest) {
        if (!(bounds instanceof OpenLayers.Bounds)) {
            bounds = new OpenLayers.Bounds(bounds);
        }
        var center = bounds.getCenterLonLat();
        if (this.baseLayer.wrapDateLine) {
            var maxExtent = this.getMaxExtent();

            //fix straddling bounds (in the case of a bbox that straddles the 
            // dateline, it's left and right boundaries will appear backwards. 
            // we fix this by allowing a right value that is greater than the
            // max value at the dateline -- this allows us to pass a valid 
            // bounds to calculate zoom)
            //
            bounds = bounds.clone();
            while (bounds.right < bounds.left) {
                bounds.right += maxExtent.getWidth();
            }
            //if the bounds was straddling (see above), then the center point 
            // we got from it was wrong. So we take our new bounds and ask it
            // for the center.
            //
            center = bounds.getCenterLonLat().wrapDateLine(maxExtent);
        }
        this.setCenter(center, this.getZoomForExtent(bounds, closest));
    },

    /** 
     * APIMethod: zoomToMaxExtent
     * Zoom to the full extent and recenter.
     *
     * Parameters:
     * options - {Object}
     * 
     * Allowed Options:
     * restricted - {Boolean} True to zoom to restricted extent if it is 
     *     set. Defaults to true.
     */
    zoomToMaxExtent: function(options) {
        //restricted is true by default
        var restricted = (options) ? options.restricted : true;

        var maxExtent = this.getMaxExtent({
            'restricted': restricted 
        });
        this.zoomToExtent(maxExtent);
    },

    /** 
     * APIMethod: zoomToScale
     * Zoom to a specified scale 
     * 
     * Parameters:
     * scale - {float}
     * closest - {Boolean} Find the zoom level that most closely fits the 
     *     specified scale. Note that this may result in a zoom that does 
     *     not exactly contain the entire extent.
     *     Default is false.
     * 
     */
    zoomToScale: function(scale, closest) {
        var res = OpenLayers.Util.getResolutionFromScale(scale, 
                                                         this.baseLayer.units);

        var halfWDeg = (this.size.w * res) / 2;
        var halfHDeg = (this.size.h * res) / 2;
        var center = this.getCachedCenter();

        var extent = new OpenLayers.Bounds(center.lon - halfWDeg,
                                           center.lat - halfHDeg,
                                           center.lon + halfWDeg,
                                           center.lat + halfHDeg);
        this.zoomToExtent(extent, closest);
    },
    
  /********************************************************/
  /*                                                      */
  /*             Translation Functions                    */
  /*                                                      */
  /*      The following functions translate between       */
  /*           LonLat, LayerPx, and ViewPortPx            */
  /*                                                      */
  /********************************************************/
      
  //
  // TRANSLATION: LonLat <-> ViewPortPx
  //

    /**
     * Method: getLonLatFromViewPortPx
     * 
     * Parameters:
     * viewPortPx - {<OpenLayers.Pixel>|Object} An OpenLayers.Pixel or
     *                                          an object with a 'x'
     *                                          and 'y' properties.
     * 
     * Returns:
     * {<OpenLayers.LonLat>} An OpenLayers.LonLat which is the passed-in view 
     *                       port <OpenLayers.Pixel>, translated into lon/lat
     *                       by the current base layer.
     */
    getLonLatFromViewPortPx: function (viewPortPx) {
        var lonlat = null; 
        if (this.baseLayer != null) {
            lonlat = this.baseLayer.getLonLatFromViewPortPx(viewPortPx);
        }
        return lonlat;
    },

    /**
     * APIMethod: getViewPortPxFromLonLat
     * 
     * Parameters:
     * lonlat - {<OpenLayers.LonLat>}
     * 
     * Returns:
     * {<OpenLayers.Pixel>} An OpenLayers.Pixel which is the passed-in 
     *                      <OpenLayers.LonLat>, translated into view port 
     *                      pixels by the current base layer.
     */
    getViewPortPxFromLonLat: function (lonlat) {
        var px = null; 
        if (this.baseLayer != null) {
            px = this.baseLayer.getViewPortPxFromLonLat(lonlat);
        }
        return px;
    },

    /**
     * Method: getZoomTargetCenter
     *
     * Parameters:
     * xy - {<OpenLayers.Pixel>} The zoom origin pixel location on the screen
     * resolution - {Float} The resolution we want to get the center for
     *
     * Returns:
     * {<OpenLayers.LonLat>} The location of the map center after the
     *     transformation described by the origin xy and the target resolution.
     */
    getZoomTargetCenter: function (xy, resolution) {
        var lonlat = null,
            size = this.getSize(),
            deltaX  = size.w/2 - xy.x,
            deltaY  = xy.y - size.h/2,
            zoomPoint = this.getLonLatFromPixel(xy);
        if (zoomPoint) {
            lonlat = new OpenLayers.LonLat(
                zoomPoint.lon + deltaX * resolution,
                zoomPoint.lat + deltaY * resolution
            );
        }
        return lonlat;
    },
        
  //
  // CONVENIENCE TRANSLATION FUNCTIONS FOR API
  //

    /**
     * APIMethod: getLonLatFromPixel
     * 
     * Parameters:
     * px - {<OpenLayers.Pixel>|Object} An OpenLayers.Pixel or an object with
     *                                  a 'x' and 'y' properties.
     *
     * Returns:
     * {<OpenLayers.LonLat>} An OpenLayers.LonLat corresponding to the given
     *                       OpenLayers.Pixel, translated into lon/lat by the 
     *                       current base layer
     */
    getLonLatFromPixel: function (px) {
        return this.getLonLatFromViewPortPx(px);
    },

    /**
     * APIMethod: getPixelFromLonLat
     * Returns a pixel location given a map location.  The map location is
     *     translated to an integer pixel location (in viewport pixel
     *     coordinates) by the current base layer.
     * 
     * Parameters:
     * lonlat - {<OpenLayers.LonLat>} A map location.
     * 
     * Returns: 
     * {<OpenLayers.Pixel>} An OpenLayers.Pixel corresponding to the 
     *     <OpenLayers.LonLat> translated into view port pixels by the current
     *     base layer.
     */
    getPixelFromLonLat: function (lonlat) {
        var px = this.getViewPortPxFromLonLat(lonlat);
        px.x = Math.round(px.x);
        px.y = Math.round(px.y);
        return px;
    },
    
    /**
     * Method: getGeodesicPixelSize
     * 
     * Parameters:
     * px - {<OpenLayers.Pixel>} The pixel to get the geodesic length for. If
     *     not provided, the center pixel of the map viewport will be used.
     * 
     * Returns:
     * {<OpenLayers.Size>} The geodesic size of the pixel in kilometers.
     */
    getGeodesicPixelSize: function(px) {
        var lonlat = px ? this.getLonLatFromPixel(px) : (
            this.getCachedCenter() || new OpenLayers.LonLat(0, 0));
        var res = this.getResolution();
        var left = lonlat.add(-res / 2, 0);
        var right = lonlat.add(res / 2, 0);
        var bottom = lonlat.add(0, -res / 2);
        var top = lonlat.add(0, res / 2);
        var dest = new OpenLayers.Projection("EPSG:4326");
        var source = this.getProjectionObject() || dest;
        if(!source.equals(dest)) {
            left.transform(source, dest);
            right.transform(source, dest);
            bottom.transform(source, dest);
            top.transform(source, dest);
        }
        
        return new OpenLayers.Size(
            OpenLayers.Util.distVincenty(left, right),
            OpenLayers.Util.distVincenty(bottom, top)
        );
    },



  //
  // TRANSLATION: ViewPortPx <-> LayerPx
  //

    /**
     * APIMethod: getViewPortPxFromLayerPx
     * 
     * Parameters:
     * layerPx - {<OpenLayers.Pixel>}
     * 
     * Returns:
     * {<OpenLayers.Pixel>} Layer Pixel translated into ViewPort Pixel 
     *                      coordinates
     */
    getViewPortPxFromLayerPx:function(layerPx) {
        var viewPortPx = null;
        if (layerPx != null) {
            var dX = this.layerContainerOriginPx.x;
            var dY = this.layerContainerOriginPx.y;
            viewPortPx = layerPx.add(dX, dY);            
        }
        return viewPortPx;
    },
    
    /**
     * APIMethod: getLayerPxFromViewPortPx
     * 
     * Parameters:
     * viewPortPx - {<OpenLayers.Pixel>}
     * 
     * Returns:
     * {<OpenLayers.Pixel>} ViewPort Pixel translated into Layer Pixel 
     *                      coordinates
     */
    getLayerPxFromViewPortPx:function(viewPortPx) {
        var layerPx = null;
        if (viewPortPx != null) {
            var dX = -this.layerContainerOriginPx.x;
            var dY = -this.layerContainerOriginPx.y;
            layerPx = viewPortPx.add(dX, dY);
            if (isNaN(layerPx.x) || isNaN(layerPx.y)) {
                layerPx = null;
            }
        }
        return layerPx;
    },
    
  //
  // TRANSLATION: LonLat <-> LayerPx
  //

    /**
     * Method: getLonLatFromLayerPx
     * 
     * Parameters:
     * px - {<OpenLayers.Pixel>}
     *
     * Returns:
     * {<OpenLayers.LonLat>}
     */
    getLonLatFromLayerPx: function (px) {
       //adjust for displacement of layerContainerDiv
       px = this.getViewPortPxFromLayerPx(px);
       return this.getLonLatFromViewPortPx(px);         
    },
    
    /**
     * APIMethod: getLayerPxFromLonLat
     * 
     * Parameters:
     * lonlat - {<OpenLayers.LonLat>} lonlat
     *
     * Returns:
     * {<OpenLayers.Pixel>} An OpenLayers.Pixel which is the passed-in 
     *                      <OpenLayers.LonLat>, translated into layer pixels 
     *                      by the current base layer
     */
    getLayerPxFromLonLat: function (lonlat) {
       //adjust for displacement of layerContainerDiv
       var px = this.getPixelFromLonLat(lonlat);
       return this.getLayerPxFromViewPortPx(px);         
    },

    /**
     * Method: applyTransform
     * Applies the given transform to the <layerContainerDiv>. This method has
     * a 2-stage fallback from translate3d/scale3d via translate/scale to plain
     * style.left/style.top, in which case no scaling is supported.
     *
     * Parameters:
     * x - {Number} x parameter for the translation. Defaults to the x value of
     *     the map's <layerContainerOriginPx>
     * y - {Number} y parameter for the translation. Defaults to the y value of
     *     the map's <layerContainerOriginPx>
     * scale - {Number} scale. Defaults to 1 if not provided.
     */
     applyTransform: function(x, y, scale) {
         scale = scale || 1;
         var origin = this.layerContainerOriginPx,
             needTransform = scale !== 1;
         x = x || origin.x;
         y = y || origin.y;
            
         var style = this.layerContainerDiv.style,
             transform = this.applyTransform.transform,
             template = this.applyTransform.template;
        
         if (transform === undefined) {
             transform = OpenLayers.Util.vendorPrefix.style('transform');
             this.applyTransform.transform = transform;
             if (transform) {
                 // Try translate3d, but only if the viewPortDiv has a transform
                 // defined in a stylesheet
                 var computedStyle = OpenLayers.Element.getStyle(this.viewPortDiv,
                     OpenLayers.Util.vendorPrefix.css('transform'));
                 if (!computedStyle || computedStyle !== 'none') {
                     template = ['translate3d(', ',0) ', 'scale3d(', ',1)'];
                     style[transform] = [template[0], '0,0', template[1]].join('');
                 }
                 // If no transform is defined in the stylesheet or translate3d
                 // does not stick, use translate and scale
                 if (!template || !~style[transform].indexOf(template[0])) {
                     template = ['translate(', ') ', 'scale(', ')'];
                 }
                 this.applyTransform.template = template;
             }
         }
         
         // If we do 3d transforms, we always want to use them. If we do 2d
         // transforms, we only use them when we need to.
         if (transform !== null && (template[0] === 'translate3d(' || needTransform === true)) {
             // Our 2d transforms are combined with style.left and style.top, so
             // adjust x and y values and set the origin as left and top
             if (needTransform === true && template[0] === 'translate(') {
                 x -= origin.x;
                 y -= origin.y;
                 style.left = origin.x + 'px';
                 style.top = origin.y + 'px';
             }
             style[transform] = [
                 template[0], x, 'px,', y, 'px', template[1],
                 template[2], scale, ',', scale, template[3]
             ].join('');
         } else {
             style.left = x + 'px';
             style.top = y + 'px';
             // We previously might have had needTransform, so remove transform
             if (transform !== null) {
                 style[transform] = '';
             }
         }
     },
    
    CLASS_NAME: "OpenLayers.Map"
});

/**
 * Constant: TILE_WIDTH
 * {Integer} 256 Default tile width (unless otherwise specified)
 */
OpenLayers.Map.TILE_WIDTH = 256;
/**
 * Constant: TILE_HEIGHT
 * {Integer} 256 Default tile height (unless otherwise specified)
 */
OpenLayers.Map.TILE_HEIGHT = 256;
/* ======================================================================
    OpenLayers/Layer.js
   ====================================================================== */

/* Copyright (c) 2006-2013 by OpenLayers Contributors (see authors.txt for
 * full list of contributors). Published under the 2-clause BSD license.
 * See license.txt in the OpenLayers distribution or repository for the
 * full text of the license. */


/**
 * @requires OpenLayers/BaseTypes/Class.js
 * @requires OpenLayers/Map.js
 * @requires OpenLayers/Projection.js
 */

/**
 * Class: OpenLayers.Layer
 */
OpenLayers.Layer = OpenLayers.Class({

    /**
     * APIProperty: id
     * {String}
     */
    id: null,

    /** 
     * APIProperty: name
     * {String}
     */
    name: null,

    /** 
     * APIProperty: div
     * {DOMElement}
     */
    div: null,

    /**
     * APIProperty: opacity
     * {Float} The layer's opacity. Float number between 0.0 and 1.0. Default
     * is 1.
     */
    opacity: 1,

    /**
     * APIProperty: alwaysInRange
     * {Boolean} If a layer's display should not be scale-based, this should 
     *     be set to true. This will cause the layer, as an overlay, to always 
     *     be 'active', by always returning true from the calculateInRange() 
     *     function. 
     * 
     *     If not explicitly specified for a layer, its value will be 
     *     determined on startup in initResolutions() based on whether or not 
     *     any scale-specific properties have been set as options on the 
     *     layer. If no scale-specific options have been set on the layer, we 
     *     assume that it should always be in range.
     * 
     *     See #987 for more info.
     */
    alwaysInRange: null,   

    /**
     * Constant: RESOLUTION_PROPERTIES
     * {Array} The properties that are used for calculating resolutions
     *     information.
     */
    RESOLUTION_PROPERTIES: [
        'scales', 'resolutions',
        'maxScale', 'minScale',
        'maxResolution', 'minResolution',
        'numZoomLevels', 'maxZoomLevel'
    ],

    /**
     * APIProperty: events
     * {<OpenLayers.Events>}
     *
     * Register a listener for a particular event with the following syntax:
     * (code)
     * layer.events.register(type, obj, listener);
     * (end)
     *
     * Listeners will be called with a reference to an event object.  The
     *     properties of this event depends on exactly what happened.
     *
     * All event objects have at least the following properties:
     * object - {Object} A reference to layer.events.object.
     * element - {DOMElement} A reference to layer.events.element.
     *
     * Supported map event types:
     * loadstart - Triggered when layer loading starts.  When using a Vector 
     *     layer with a Fixed or BBOX strategy, the event object includes 
     *     a *filter* property holding the OpenLayers.Filter used when 
     *     calling read on the protocol.
     * loadend - Triggered when layer loading ends.  When using a Vector layer
     *     with a Fixed or BBOX strategy, the event object includes a 
     *     *response* property holding an OpenLayers.Protocol.Response object.
     * visibilitychanged - Triggered when the layer's visibility property is
     *     changed, e.g. by turning the layer on or off in the layer switcher.
     *     Note that the actual visibility of the layer can also change if it
     *     gets out of range (see <calculateInRange>). If you also want to catch
     *     these cases, register for the map's 'changelayer' event instead.
     * move - Triggered when layer moves (triggered with every mousemove
     *     during a drag).
     * moveend - Triggered when layer is done moving, object passed as
     *     argument has a zoomChanged boolean property which tells that the
     *     zoom has changed.
     * added - Triggered after the layer is added to a map.  Listeners will
     *     receive an object with a *map* property referencing the map and a
     *     *layer* property referencing the layer.
     * removed - Triggered after the layer is removed from the map.  Listeners
     *     will receive an object with a *map* property referencing the map and
     *     a *layer* property referencing the layer.
     */
    events: null,

    /**
     * APIProperty: map
     * {<OpenLayers.Map>} This variable is set when the layer is added to 
     *     the map, via the accessor function setMap().
     */
    map: null,
    
    /**
     * APIProperty: isBaseLayer
     * {Boolean} Whether or not the layer is a base layer. This should be set 
     *     individually by all subclasses. Default is false
     */
    isBaseLayer: false,
 
    /**
     * Property: alpha
     * {Boolean} The layer's images have an alpha channel.  Default is false.
     */
    alpha: false,

    /** 
     * APIProperty: displayInLayerSwitcher
     * {Boolean} Display the layer's name in the layer switcher.  Default is
     *     true.
     */
    displayInLayerSwitcher: true,

    /**
     * APIProperty: visibility
     * {Boolean} The layer should be displayed in the map.  Default is true.
     */
    visibility: true,

    /**
     * APIProperty: attribution
     * {String} Attribution string, displayed when an 
     *     <OpenLayers.Control.Attribution> has been added to the map.
     */
    attribution: null, 

    /** 
     * Property: inRange
     * {Boolean} The current map resolution is within the layer's min/max 
     *     range. This is set in <OpenLayers.Map.setCenter> whenever the zoom 
     *     changes.
     */
    inRange: false,
    
    /**
     * Propery: imageSize
     * {<OpenLayers.Size>} For layers with a gutter, the image is larger than 
     *     the tile by twice the gutter in each dimension.
     */
    imageSize: null,
    
  // OPTIONS

    /** 
     * Property: options
     * {Object} An optional object whose properties will be set on the layer.
     *     Any of the layer properties can be set as a property of the options
     *     object and sent to the constructor when the layer is created.
     */
    options: null,

    /**
     * APIProperty: eventListeners
     * {Object} If set as an option at construction, the eventListeners
     *     object will be registered with <OpenLayers.Events.on>.  Object
     *     structure must be a listeners object as shown in the example for
     *     the events.on method.
     */
    eventListeners: null,

    /**
     * APIProperty: gutter
     * {Integer} Determines the width (in pixels) of the gutter around image
     *     tiles to ignore.  By setting this property to a non-zero value,
     *     images will be requested that are wider and taller than the tile
     *     size by a value of 2 x gutter.  This allows artifacts of rendering
     *     at tile edges to be ignored.  Set a gutter value that is equal to
     *     half the size of the widest symbol that needs to be displayed.
     *     Defaults to zero.  Non-tiled layers always have zero gutter.
     */ 
    gutter: 0, 

    /**
     * APIProperty: projection
     * {<OpenLayers.Projection>} or {<String>} Specifies the projection of the layer.
     *     Can be set in the layer options. If not specified in the layer options,
     *     it is set to the default projection specified in the map,
     *     when the layer is added to the map.
     *     Projection along with default maxExtent and resolutions
     *     are set automatically with commercial baselayers in EPSG:3857,
     *     such as Google, Bing and OpenStreetMap, and do not need to be specified.
     *     Otherwise, if specifying projection, also set maxExtent,
     *     maxResolution or resolutions as appropriate.
     *     When using vector layers with strategies, layer projection should be set
     *     to the projection of the source data if that is different from the map default.
     * 
     *     Can be either a string or an <OpenLayers.Projection> object;
     *     if a string is passed, will be converted to an object when
     *     the layer is added to the map.
     * 
     */
    projection: null,    
    
    /**
     * APIProperty: units
     * {String} The layer map units.  Defaults to null.  Possible values
     *     are 'degrees' (or 'dd'), 'm', 'ft', 'km', 'mi', 'inches'.
     *     Normally taken from the projection.
     *     Only required if both map and layers do not define a projection,
     *     or if they define a projection which does not define units.
     */
    units: null,

    /**
     * APIProperty: scales
     * {Array}  An array of map scales in descending order.  The values in the
     *     array correspond to the map scale denominator.  Note that these
     *     values only make sense if the display (monitor) resolution of the
     *     client is correctly guessed by whomever is configuring the
     *     application.  In addition, the units property must also be set.
     *     Use <resolutions> instead wherever possible.
     */
    scales: null,

    /**
     * APIProperty: resolutions
     * {Array} A list of map resolutions (map units per pixel) in descending
     *     order.  If this is not set in the layer constructor, it will be set
     *     based on other resolution related properties (maxExtent,
     *     maxResolution, maxScale, etc.).
     */
    resolutions: null,
    
    /**
     * APIProperty: maxExtent
     * {<OpenLayers.Bounds>|Array} If provided as an array, the array
     *     should consist of four values (left, bottom, right, top).
     *     The maximum extent for the layer.  Defaults to null.
     * 
     *     The center of these bounds will not stray outside
     *     of the viewport extent during panning.  In addition, if
     *     <displayOutsideMaxExtent> is set to false, data will not be
     *     requested that falls completely outside of these bounds.
     */
    maxExtent: null,
    
    /**
     * APIProperty: minExtent
     * {<OpenLayers.Bounds>|Array} If provided as an array, the array
     *     should consist of four values (left, bottom, right, top).
     *     The minimum extent for the layer.  Defaults to null.
     */
    minExtent: null,
    
    /**
     * APIProperty: maxResolution
     * {Float} Default max is 360 deg / 256 px, which corresponds to
     *     zoom level 0 on gmaps.  Specify a different value in the layer 
     *     options if you are not using the default <OpenLayers.Map.tileSize>
     *     and displaying the whole world.
     */
    maxResolution: null,

    /**
     * APIProperty: minResolution
     * {Float}
     */
    minResolution: null,

    /**
     * APIProperty: numZoomLevels
     * {Integer}
     */
    numZoomLevels: null,
    
    /**
     * APIProperty: minScale
     * {Float}
     */
    minScale: null,
    
    /**
     * APIProperty: maxScale
     * {Float}
     */
    maxScale: null,

    /**
     * APIProperty: displayOutsideMaxExtent
     * {Boolean} Request map tiles that are completely outside of the max 
     *     extent for this layer. Defaults to false.
     */
    displayOutsideMaxExtent: false,

    /**
     * APIProperty: wrapDateLine
     * {Boolean} Wraps the world at the international dateline, so the map can
     * be panned infinitely in longitudinal direction. Only use this on the
     * base layer, and only if the layer's maxExtent equals the world bounds.
     * #487 for more info.   
     */
    wrapDateLine: false,
    
    /**
     * Property: metadata
     * {Object} This object can be used to store additional information on a
     *     layer object.
     */
    metadata: null,
    
    /**
     * Constructor: OpenLayers.Layer
     *
     * Parameters:
     * name - {String} The layer name
     * options - {Object} Hashtable of extra options to tag onto the layer
     */
    initialize: function(name, options) {

        this.metadata = {};
        
        options = OpenLayers.Util.extend({}, options);
        // make sure we respect alwaysInRange if set on the prototype
        if (this.alwaysInRange != null) {
            options.alwaysInRange = this.alwaysInRange;
        }
        this.addOptions(options);

        this.name = name;
        
        if (this.id == null) {

            this.id = OpenLayers.Util.createUniqueID(this.CLASS_NAME + "_");

            this.div = OpenLayers.Util.createDiv(this.id);
            this.div.style.width = "100%";
            this.div.style.height = "100%";
            this.div.dir = "ltr";

            this.events = new OpenLayers.Events(this, this.div);
            if(this.eventListeners instanceof Object) {
                this.events.on(this.eventListeners);
            }

        }
    },
    
    /**
     * Method: destroy
     * Destroy is a destructor: this is to alleviate cyclic references which
     *     the Javascript garbage cleaner can not take care of on its own.
     *
     * Parameters:
     * setNewBaseLayer - {Boolean} Set a new base layer when this layer has
     *     been destroyed.  Default is true.
     */
    destroy: function(setNewBaseLayer) {
        if (setNewBaseLayer == null) {
            setNewBaseLayer = true;
        }
        if (this.map != null) {
            this.map.removeLayer(this, setNewBaseLayer);
        }
        this.projection = null;
        this.map = null;
        this.name = null;
        this.div = null;
        this.options = null;

        if (this.events) {
            if(this.eventListeners) {
                this.events.un(this.eventListeners);
            }
            this.events.destroy();
        }
        this.eventListeners = null;
        this.events = null;
    },
    
   /**
    * Method: clone
    *
    * Parameters:
    * obj - {<OpenLayers.Layer>} The layer to be cloned
    *
    * Returns:
    * {<OpenLayers.Layer>} An exact clone of this <OpenLayers.Layer>
    */
    clone: function (obj) {
        
        if (obj == null) {
            obj = new OpenLayers.Layer(this.name, this.getOptions());
        }
        
        // catch any randomly tagged-on properties
        OpenLayers.Util.applyDefaults(obj, this);
        
        // a cloned layer should never have its map property set
        //  because it has not been added to a map yet. 
        obj.map = null;
        
        return obj;
    },
    
    /**
     * Method: getOptions
     * Extracts an object from the layer with the properties that were set as
     *     options, but updates them with the values currently set on the
     *     instance.
     * 
     * Returns:
     * {Object} the <options> of the layer, representing the current state.
     */
    getOptions: function() {
        var options = {};
        for(var o in this.options) {
            options[o] = this[o];
        }
        return options;
    },
    
    /** 
     * APIMethod: setName
     * Sets the new layer name for this layer.  Can trigger a changelayer event
     *     on the map.
     *
     * Parameters:
     * newName - {String} The new name.
     */
    setName: function(newName) {
        if (newName != this.name) {
            this.name = newName;
            if (this.map != null) {
                this.map.events.triggerEvent("changelayer", {
                    layer: this,
                    property: "name"
                });
            }
        }
    },    
    
   /**
    * APIMethod: addOptions
    * 
    * Parameters:
    * newOptions - {Object}
    * reinitialize - {Boolean} If set to true, and if resolution options of the
    *     current baseLayer were changed, the map will be recentered to make
    *     sure that it is displayed with a valid resolution, and a
    *     changebaselayer event will be triggered.
    */
    addOptions: function (newOptions, reinitialize) {

        if (this.options == null) {
            this.options = {};
        }
        
        if (newOptions) {
            // make sure this.projection references a projection object
            if(typeof newOptions.projection == "string") {
                newOptions.projection = new OpenLayers.Projection(newOptions.projection);
            }
            if (newOptions.projection) {
                // get maxResolution, units and maxExtent from projection defaults if
                // they are not defined already
                OpenLayers.Util.applyDefaults(newOptions,
                    OpenLayers.Projection.defaults[newOptions.projection.getCode()]);
            }
            // allow array for extents
            if (newOptions.maxExtent && !(newOptions.maxExtent instanceof OpenLayers.Bounds)) {
                newOptions.maxExtent = new OpenLayers.Bounds(newOptions.maxExtent);
            }
            if (newOptions.minExtent && !(newOptions.minExtent instanceof OpenLayers.Bounds)) {
                newOptions.minExtent = new OpenLayers.Bounds(newOptions.minExtent);
            }
        }

        // update our copy for clone
        OpenLayers.Util.extend(this.options, newOptions);

        // add new options to this
        OpenLayers.Util.extend(this, newOptions);
        
        // get the units from the projection, if we have a projection
        // and it it has units
        if(this.projection && this.projection.getUnits()) {
            this.units = this.projection.getUnits();
        }

        // re-initialize resolutions if necessary, i.e. if any of the
        // properties of the "properties" array defined below is set
        // in the new options
        if(this.map) {
            // store current resolution so we can try to restore it later
            var resolution = this.map.getResolution();
            var properties = this.RESOLUTION_PROPERTIES.concat(
                ["projection", "units", "minExtent", "maxExtent"]
            );
            for(var o in newOptions) {
                if(newOptions.hasOwnProperty(o) &&
                   OpenLayers.Util.indexOf(properties, o) >= 0) {

                    this.initResolutions();
                    if (reinitialize && this.map.baseLayer === this) {
                        // update map position, and restore previous resolution
                        this.map.setCenter(this.map.getCenter(),
                            this.map.getZoomForResolution(resolution),
                            false, true
                        );
                        // trigger a changebaselayer event to make sure that
                        // all controls (especially
                        // OpenLayers.Control.PanZoomBar) get notified of the
                        // new options
                        this.map.events.triggerEvent("changebaselayer", {
                            layer: this
                        });
                    }
                    break;
                }
            }
        }
    },

    /**
     * APIMethod: onMapResize
     * This function can be implemented by subclasses
     */
    onMapResize: function() {
        //this function can be implemented by subclasses  
    },

    /**
     * APIMethod: redraw
     * Redraws the layer.  Returns true if the layer was redrawn, false if not.
     *
     * Returns:
     * {Boolean} The layer was redrawn.
     */
    redraw: function() {
        var redrawn = false;
        if (this.map) {

            // min/max Range may have changed
            this.inRange = this.calculateInRange();

            // map's center might not yet be set
            var extent = this.getExtent();

            if (extent && this.inRange && this.visibility) {
                var zoomChanged = true;
                this.moveTo(extent, zoomChanged, false);
                this.events.triggerEvent("moveend",
                    {"zoomChanged": zoomChanged});
                redrawn = true;
            }
        }
        return redrawn;
    },

    /**
     * Method: moveTo
     * 
     * Parameters:
     * bounds - {<OpenLayers.Bounds>}
     * zoomChanged - {Boolean} Tells when zoom has changed, as layers have to
     *     do some init work in that case.
     * dragging - {Boolean}
     */
    moveTo:function(bounds, zoomChanged, dragging) {
        var display = this.visibility;
        if (!this.isBaseLayer) {
            display = display && this.inRange;
        }
        this.display(display);
    },

    /**
     * Method: moveByPx
     * Move the layer based on pixel vector. To be implemented by subclasses.
     *
     * Parameters:
     * dx - {Number} The x coord of the displacement vector.
     * dy - {Number} The y coord of the displacement vector.
     */
    moveByPx: function(dx, dy) {
    },

    /**
     * Method: setMap
     * Set the map property for the layer. This is done through an accessor
     *     so that subclasses can override this and take special action once 
     *     they have their map variable set. 
     * 
     *     Here we take care to bring over any of the necessary default 
     *     properties from the map. 
     * 
     * Parameters:
     * map - {<OpenLayers.Map>}
     */
    setMap: function(map) {
        if (this.map == null) {
        
            this.map = map;
            
            // grab some essential layer data from the map if it hasn't already
            //  been set
            this.maxExtent = this.maxExtent || this.map.maxExtent;
            this.minExtent = this.minExtent || this.map.minExtent;

            this.projection = this.projection || this.map.projection;
            if (typeof this.projection == "string") {
                this.projection = new OpenLayers.Projection(this.projection);
            }

            // Check the projection to see if we can get units -- if not, refer
            // to properties.
            this.units = this.projection.getUnits() ||
                         this.units || this.map.units;
            
            this.initResolutions();
            
            if (!this.isBaseLayer) {
                this.inRange = this.calculateInRange();
                var show = ((this.visibility) && (this.inRange));
                this.div.style.display = show ? "" : "none";
            }
            
            // deal with gutters
            this.setTileSize();
        }
    },
    
    /**
     * Method: afterAdd
     * Called at the end of the map.addLayer sequence.  At this point, the map
     *     will have a base layer.  To be overridden by subclasses.
     */
    afterAdd: function() {
    },
    
    /**
     * APIMethod: removeMap
     * Just as setMap() allows each layer the possibility to take a 
     *     personalized action on being added to the map, removeMap() allows
     *     each layer to take a personalized action on being removed from it. 
     *     For now, this will be mostly unused, except for the EventPane layer,
     *     which needs this hook so that it can remove the special invisible
     *     pane. 
     * 
     * Parameters:
     * map - {<OpenLayers.Map>}
     */
    removeMap: function(map) {
        //to be overridden by subclasses
    },
    
    /**
     * APIMethod: getImageSize
     *
     * Parameters:
     * bounds - {<OpenLayers.Bounds>} optional tile bounds, can be used
     *     by subclasses that have to deal with different tile sizes at the
     *     layer extent edges (e.g. Zoomify)
     * 
     * Returns:
     * {<OpenLayers.Size>} The size that the image should be, taking into 
     *     account gutters.
     */ 
    getImageSize: function(bounds) { 
        return (this.imageSize || this.tileSize); 
    },    
  
    /**
     * APIMethod: setTileSize
     * Set the tile size based on the map size.  This also sets layer.imageSize
     *     or use by Tile.Image.
     * 
     * Parameters:
     * size - {<OpenLayers.Size>}
     */
    setTileSize: function(size) {
        var tileSize = (size) ? size :
                                ((this.tileSize) ? this.tileSize :
                                                   this.map.getTileSize());
        this.tileSize = tileSize;
        if(this.gutter) {
          // layers with gutters need non-null tile sizes
          //if(tileSize == null) {
          //    OpenLayers.console.error("Error in layer.setMap() for " +
          //                              this.name + ": layers with " +
          //                              "gutters need non-null tile sizes");
          //}
            this.imageSize = new OpenLayers.Size(tileSize.w + (2*this.gutter), 
                                                 tileSize.h + (2*this.gutter)); 
        }
    },

    /**
     * APIMethod: getVisibility
     * 
     * Returns:
     * {Boolean} The layer should be displayed (if in range).
     */
    getVisibility: function() {
        return this.visibility;
    },

    /** 
     * APIMethod: setVisibility
     * Set the visibility flag for the layer and hide/show & redraw 
     *     accordingly. Fire event unless otherwise specified
     * 
     * Note that visibility is no longer simply whether or not the layer's
     *     style.display is set to "block". Now we store a 'visibility' state 
     *     property on the layer class, this allows us to remember whether or 
     *     not we *desire* for a layer to be visible. In the case where the 
     *     map's resolution is out of the layer's range, this desire may be 
     *     subverted.
     * 
     * Parameters:
     * visibility - {Boolean} Whether or not to display the layer (if in range)
     */
    setVisibility: function(visibility) {
        if (visibility != this.visibility) {
            this.visibility = visibility;
            this.display(visibility);
            this.redraw();
            if (this.map != null) {
                this.map.events.triggerEvent("changelayer", {
                    layer: this,
                    property: "visibility"
                });
            }
            this.events.triggerEvent("visibilitychanged");
        }
    },

    /** 
     * APIMethod: display
     * Hide or show the Layer. This is designed to be used internally, and 
     *     is not generally the way to enable or disable the layer. For that,
     *     use the setVisibility function instead..
     * 
     * Parameters:
     * display - {Boolean}
     */
    display: function(display) {
        if (display != (this.div.style.display != "none")) {
            this.div.style.display = (display && this.calculateInRange()) ? "block" : "none";
        }
    },

    /**
     * APIMethod: calculateInRange
     * 
     * Returns:
     * {Boolean} The layer is displayable at the current map's current
     *     resolution. Note that if 'alwaysInRange' is true for the layer, 
     *     this function will always return true.
     */
    calculateInRange: function() {
        var inRange = false;

        if (this.alwaysInRange) {
            inRange = true;
        } else {
            if (this.map) {
                var resolution = this.map.getResolution();
                inRange = ( (resolution >= this.minResolution) &&
                            (resolution <= this.maxResolution) );
            }
        }
        return inRange;
    },

    /** 
     * APIMethod: setIsBaseLayer
     * 
     * Parameters:
     * isBaseLayer - {Boolean}
     */
    setIsBaseLayer: function(isBaseLayer) {
        if (isBaseLayer != this.isBaseLayer) {
            this.isBaseLayer = isBaseLayer;
            if (this.map != null) {
                this.map.events.triggerEvent("changebaselayer", {
                    layer: this
                });
            }
        }
    },

  /********************************************************/
  /*                                                      */
  /*                 Baselayer Functions                  */
  /*                                                      */
  /********************************************************/
  
    /** 
     * Method: initResolutions
     * This method's responsibility is to set up the 'resolutions' array 
     *     for the layer -- this array is what the layer will use to interface
     *     between the zoom levels of the map and the resolution display 
     *     of the layer.
     * 
     * The user has several options that determine how the array is set up.
     *  
     * For a detailed explanation, see the following wiki from the 
     *     openlayers.org homepage:
     *     http://trac.openlayers.org/wiki/SettingZoomLevels
     */
    initResolutions: function() {

        // ok we want resolutions, here's our strategy:
        //
        // 1. if resolutions are defined in the layer config, use them
        // 2. else, if scales are defined in the layer config then derive
        //    resolutions from these scales
        // 3. else, attempt to calculate resolutions from maxResolution,
        //    minResolution, numZoomLevels, maxZoomLevel set in the
        //    layer config
        // 4. if we still don't have resolutions, and if resolutions
        //    are defined in the same, use them
        // 5. else, if scales are defined in the map then derive
        //    resolutions from these scales
        // 6. else, attempt to calculate resolutions from maxResolution,
        //    minResolution, numZoomLevels, maxZoomLevel set in the
        //    map
        // 7. hope for the best!

        var i, len, p;
        var props = {}, alwaysInRange = true;

        // get resolution data from layer config
        // (we also set alwaysInRange in the layer as appropriate)
        for(i=0, len=this.RESOLUTION_PROPERTIES.length; i<len; i++) {
            p = this.RESOLUTION_PROPERTIES[i];
            props[p] = this.options[p];
            if(alwaysInRange && this.options[p]) {
                alwaysInRange = false;
            }
        }
        if(this.options.alwaysInRange == null) {
            this.alwaysInRange = alwaysInRange;
        }

        // if we don't have resolutions then attempt to derive them from scales
        if(props.resolutions == null) {
            props.resolutions = this.resolutionsFromScales(props.scales);
        }

        // if we still don't have resolutions then attempt to calculate them
        if(props.resolutions == null) {
            props.resolutions = this.calculateResolutions(props);
        }

        // if we couldn't calculate resolutions then we look at we have
        // in the map
        if(props.resolutions == null) {
            for(i=0, len=this.RESOLUTION_PROPERTIES.length; i<len; i++) {
                p = this.RESOLUTION_PROPERTIES[i];
                props[p] = this.options[p] != null ?
                    this.options[p] : this.map[p];
            }
            if(props.resolutions == null) {
                props.resolutions = this.resolutionsFromScales(props.scales);
            }
            if(props.resolutions == null) {
                props.resolutions = this.calculateResolutions(props);
            }
        }

        // ok, we new need to set properties in the instance

        // get maxResolution from the config if it's defined there
        var maxResolution;
        if(this.options.maxResolution &&
           this.options.maxResolution !== "auto") {
            maxResolution = this.options.maxResolution;
        }
        if(this.options.minScale) {
            maxResolution = OpenLayers.Util.getResolutionFromScale(
                this.options.minScale, this.units);
        }

        // get minResolution from the config if it's defined there
        var minResolution;
        if(this.options.minResolution &&
           this.options.minResolution !== "auto") {
            minResolution = this.options.minResolution;
        }
        if(this.options.maxScale) {
            minResolution = OpenLayers.Util.getResolutionFromScale(
                this.options.maxScale, this.units);
        }

        if(props.resolutions) {

            //sort resolutions array descendingly
            props.resolutions.sort(function(a, b) {
                return (b - a);
            });

            // if we still don't have a maxResolution get it from the
            // resolutions array
            if(!maxResolution) {
                maxResolution = props.resolutions[0];
            }

            // if we still don't have a minResolution get it from the
            // resolutions array
            if(!minResolution) {
                var lastIdx = props.resolutions.length - 1;
                minResolution = props.resolutions[lastIdx];
            }
        }

        this.resolutions = props.resolutions;
        if(this.resolutions) {
            len = this.resolutions.length;
            this.scales = new Array(len);
            for(i=0; i<len; i++) {
                this.scales[i] = OpenLayers.Util.getScaleFromResolution(
                    this.resolutions[i], this.units);
            }
            this.numZoomLevels = len;
        }
        this.minResolution = minResolution;
        if(minResolution) {
            this.maxScale = OpenLayers.Util.getScaleFromResolution(
                minResolution, this.units);
        }
        this.maxResolution = maxResolution;
        if(maxResolution) {
            this.minScale = OpenLayers.Util.getScaleFromResolution(
                maxResolution, this.units);
        }
    },

    /**
     * Method: resolutionsFromScales
     * Derive resolutions from scales.
     *
     * Parameters:
     * scales - {Array(Number)} Scales
     *
     * Returns
     * {Array(Number)} Resolutions
     */
    resolutionsFromScales: function(scales) {
        if(scales == null) {
            return;
        }
        var resolutions, i, len;
        len = scales.length;
        resolutions = new Array(len);
        for(i=0; i<len; i++) {
            resolutions[i] = OpenLayers.Util.getResolutionFromScale(
                scales[i], this.units);
        }
        return resolutions;
    },

    /**
     * Method: calculateResolutions
     * Calculate resolutions based on the provided properties.
     *
     * Parameters:
     * props - {Object} Properties
     *
     * Returns:
     * {Array({Number})} Array of resolutions.
     */
    calculateResolutions: function(props) {

        var viewSize, wRes, hRes;

        // determine maxResolution
        var maxResolution = props.maxResolution;
        if(props.minScale != null) {
            maxResolution =
                OpenLayers.Util.getResolutionFromScale(props.minScale,
                                                       this.units);
        } else if(maxResolution == "auto" && this.maxExtent != null) {
            viewSize = this.map.getSize();
            wRes = this.maxExtent.getWidth() / viewSize.w;
            hRes = this.maxExtent.getHeight() / viewSize.h;
            maxResolution = Math.max(wRes, hRes);
        }

        // determine minResolution
        var minResolution = props.minResolution;
        if(props.maxScale != null) {
            minResolution =
                OpenLayers.Util.getResolutionFromScale(props.maxScale,
                                                       this.units);
        } else if(props.minResolution == "auto" && this.minExtent != null) {
            viewSize = this.map.getSize();
            wRes = this.minExtent.getWidth() / viewSize.w;
            hRes = this.minExtent.getHeight()/ viewSize.h;
            minResolution = Math.max(wRes, hRes);
        }

        if(typeof maxResolution !== "number" &&
           typeof minResolution !== "number" &&
           this.maxExtent != null) {
            // maxResolution for default grid sets assumes that at zoom
            // level zero, the whole world fits on one tile.
            var tileSize = this.map.getTileSize();
            maxResolution = Math.max(
                this.maxExtent.getWidth() / tileSize.w,
                this.maxExtent.getHeight() / tileSize.h
            );
        }

        // determine numZoomLevels
        var maxZoomLevel = props.maxZoomLevel;
        var numZoomLevels = props.numZoomLevels;
        if(typeof minResolution === "number" &&
           typeof maxResolution === "number" && numZoomLevels === undefined) {
            var ratio = maxResolution / minResolution;
            numZoomLevels = Math.floor(Math.log(ratio) / Math.log(2)) + 1;
        } else if(numZoomLevels === undefined && maxZoomLevel != null) {
            numZoomLevels = maxZoomLevel + 1;
        }

        // are we able to calculate resolutions?
        if(typeof numZoomLevels !== "number" || numZoomLevels <= 0 ||
           (typeof maxResolution !== "number" &&
                typeof minResolution !== "number")) {
            return;
        }

        // now we have numZoomLevels and at least one of maxResolution
        // or minResolution, we can populate the resolutions array

        var resolutions = new Array(numZoomLevels);
        var base = 2;
        if(typeof minResolution == "number" &&
           typeof maxResolution == "number") {
            // if maxResolution and minResolution are set, we calculate
            // the base for exponential scaling that starts at
            // maxResolution and ends at minResolution in numZoomLevels
            // steps.
            base = Math.pow(
                    (maxResolution / minResolution),
                (1 / (numZoomLevels - 1))
            );
        }

        var i;
        if(typeof maxResolution === "number") {
            for(i=0; i<numZoomLevels; i++) {
                resolutions[i] = maxResolution / Math.pow(base, i);
            }
        } else {
            for(i=0; i<numZoomLevels; i++) {
                resolutions[numZoomLevels - 1 - i] =
                    minResolution * Math.pow(base, i);
            }
        }

        return resolutions;
    },

    /**
     * APIMethod: getResolution
     * 
     * Returns:
     * {Float} The currently selected resolution of the map, taken from the
     *     resolutions array, indexed by current zoom level.
     */
    getResolution: function() {
        var zoom = this.map.getZoom();
        return this.getResolutionForZoom(zoom);
    },

    /** 
     * APIMethod: getExtent
     * 
     * Returns:
     * {<OpenLayers.Bounds>} A Bounds object which represents the lon/lat 
     *     bounds of the current viewPort.
     */
    getExtent: function() {
        // just use stock map calculateBounds function -- passing no arguments
        //  means it will user map's current center & resolution
        //
        return this.map.calculateBounds();
    },

    /**
     * APIMethod: getZoomForExtent
     * 
     * Parameters:
     * extent - {<OpenLayers.Bounds>}
     * closest - {Boolean} Find the zoom level that most closely fits the 
     *     specified bounds. Note that this may result in a zoom that does 
     *     not exactly contain the entire extent.
     *     Default is false.
     *
     * Returns:
     * {Integer} The index of the zoomLevel (entry in the resolutions array) 
     *     for the passed-in extent. We do this by calculating the ideal 
     *     resolution for the given extent (based on the map size) and then 
     *     calling getZoomForResolution(), passing along the 'closest'
     *     parameter.
     */
    getZoomForExtent: function(extent, closest) {
        var viewSize = this.map.getSize();
        var idealResolution = Math.max( extent.getWidth()  / viewSize.w,
                                        extent.getHeight() / viewSize.h );

        return this.getZoomForResolution(idealResolution, closest);
    },
    
    /** 
     * Method: getDataExtent
     * Calculates the max extent which includes all of the data for the layer.
     *     This function is to be implemented by subclasses.
     * 
     * Returns:
     * {<OpenLayers.Bounds>}
     */
    getDataExtent: function () {
        //to be implemented by subclasses
    },

    /**
     * APIMethod: getResolutionForZoom
     * 
     * Parameters:
     * zoom - {Float}
     * 
     * Returns:
     * {Float} A suitable resolution for the specified zoom.
     */
    getResolutionForZoom: function(zoom) {
        zoom = Math.max(0, Math.min(zoom, this.resolutions.length - 1));
        var resolution;
        if(this.map.fractionalZoom) {
            var low = Math.floor(zoom);
            var high = Math.ceil(zoom);
            resolution = this.resolutions[low] -
                ((zoom-low) * (this.resolutions[low]-this.resolutions[high]));
        } else {
            resolution = this.resolutions[Math.round(zoom)];
        }
        return resolution;
    },

    /**
     * APIMethod: getZoomForResolution
     * 
     * Parameters:
     * resolution - {Float}
     * closest - {Boolean} Find the zoom level that corresponds to the absolute 
     *     closest resolution, which may result in a zoom whose corresponding
     *     resolution is actually smaller than we would have desired (if this
     *     is being called from a getZoomForExtent() call, then this means that
     *     the returned zoom index might not actually contain the entire 
     *     extent specified... but it'll be close).
     *     Default is false.
     * 
     * Returns:
     * {Integer} The index of the zoomLevel (entry in the resolutions array) 
     *     that corresponds to the best fit resolution given the passed in 
     *     value and the 'closest' specification.
     */
    getZoomForResolution: function(resolution, closest) {
        var zoom, i, len;
        if(this.map.fractionalZoom) {
            var lowZoom = 0;
            var highZoom = this.resolutions.length - 1;
            var highRes = this.resolutions[lowZoom];
            var lowRes = this.resolutions[highZoom];
            var res;
            for(i=0, len=this.resolutions.length; i<len; ++i) {
                res = this.resolutions[i];
                if(res >= resolution) {
                    highRes = res;
                    lowZoom = i;
                }
                if(res <= resolution) {
                    lowRes = res;
                    highZoom = i;
                    break;
                }
            }
            var dRes = highRes - lowRes;
            if(dRes > 0) {
                zoom = lowZoom + ((highRes - resolution) / dRes);
            } else {
                zoom = lowZoom;
            }
        } else {
            var diff;
            var minDiff = Number.POSITIVE_INFINITY;
            for(i=0, len=this.resolutions.length; i<len; i++) {            
                if (closest) {
                    diff = Math.abs(this.resolutions[i] - resolution);
                    if (diff > minDiff) {
                        break;
                    }
                    minDiff = diff;
                } else {
                    if (this.resolutions[i] < resolution) {
                        break;
                    }
                }
            }
            zoom = Math.max(0, i-1);
        }
        return zoom;
    },
    
    /**
     * APIMethod: getLonLatFromViewPortPx
     * 
     * Parameters:
     * viewPortPx - {<OpenLayers.Pixel>|Object} An OpenLayers.Pixel or
     *                                          an object with a 'x'
     *                                          and 'y' properties.
     *
     * Returns:
     * {<OpenLayers.LonLat>} An OpenLayers.LonLat which is the passed-in 
     *     view port <OpenLayers.Pixel>, translated into lon/lat by the layer.
     */
    getLonLatFromViewPortPx: function (viewPortPx) {
        var lonlat = null;
        var map = this.map;
        if (viewPortPx != null && map.minPx) {
            var res = map.getResolution();
            var maxExtent = map.getMaxExtent({restricted: true});
            var lon = (viewPortPx.x - map.minPx.x) * res + maxExtent.left;
            var lat = (map.minPx.y - viewPortPx.y) * res + maxExtent.top;
            lonlat = new OpenLayers.LonLat(lon, lat);

            if (this.wrapDateLine) {
                lonlat = lonlat.wrapDateLine(this.maxExtent);
            }
        }
        return lonlat;
    },

    /**
     * APIMethod: getViewPortPxFromLonLat
     * Returns a pixel location given a map location.  This method will return
     *     fractional pixel values.
     * 
     * Parameters:
     * lonlat - {<OpenLayers.LonLat>|Object} An OpenLayers.LonLat or
     *                                       an object with a 'lon'
     *                                       and 'lat' properties.
     *
     * Returns: 
     * {<OpenLayers.Pixel>} An <OpenLayers.Pixel> which is the passed-in 
     *     lonlat translated into view port pixels.
     */
    getViewPortPxFromLonLat: function (lonlat, resolution) {
        var px = null; 
        if (lonlat != null) {
            resolution = resolution || this.map.getResolution();
            var extent = this.map.calculateBounds(null, resolution);
            px = new OpenLayers.Pixel(
                (1/resolution * (lonlat.lon - extent.left)),
                (1/resolution * (extent.top - lonlat.lat))
            );    
        }
        return px;
    },
    
    /**
     * APIMethod: setOpacity
     * Sets the opacity for the entire layer (all images)
     * 
     * Parameters:
     * opacity - {Float}
     */
    setOpacity: function(opacity) {
        if (opacity != this.opacity) {
            this.opacity = opacity;
            var childNodes = this.div.childNodes;
            for(var i = 0, len = childNodes.length; i < len; ++i) {
                var element = childNodes[i].firstChild || childNodes[i];
                var lastChild = childNodes[i].lastChild;
                //TODO de-uglify this
                if (lastChild && lastChild.nodeName.toLowerCase() === "iframe") {
                    element = lastChild.parentNode;
                }
                OpenLayers.Util.modifyDOMElement(element, null, null, null, 
                                                 null, null, null, opacity);
            }
            if (this.map != null) {
                this.map.events.triggerEvent("changelayer", {
                    layer: this,
                    property: "opacity"
                });
            }
        }
    },

    /**
     * Method: getZIndex
     * 
     * Returns: 
     * {Integer} the z-index of this layer
     */    
    getZIndex: function () {
        return this.div.style.zIndex;
    },

    /**
     * Method: setZIndex
     * 
     * Parameters: 
     * zIndex - {Integer}
     */    
    setZIndex: function (zIndex) {
        this.div.style.zIndex = zIndex;
    },

    /**
     * Method: adjustBounds
     * This function will take a bounds, and if wrapDateLine option is set
     *     on the layer, it will return a bounds which is wrapped around the 
     *     world. We do not wrap for bounds which *cross* the 
     *     maxExtent.left/right, only bounds which are entirely to the left 
     *     or entirely to the right.
     * 
     * Parameters:
     * bounds - {<OpenLayers.Bounds>}
     */
    adjustBounds: function (bounds) {

        if (this.gutter) {
            // Adjust the extent of a bounds in map units by the 
            // layer's gutter in pixels.
            var mapGutter = this.gutter * this.map.getResolution();
            bounds = new OpenLayers.Bounds(bounds.left - mapGutter,
                                           bounds.bottom - mapGutter,
                                           bounds.right + mapGutter,
                                           bounds.top + mapGutter);
        }

        if (this.wrapDateLine) {
            // wrap around the date line, within the limits of rounding error
            var wrappingOptions = { 
                'rightTolerance':this.getResolution(),
                'leftTolerance':this.getResolution()
            };    
            bounds = bounds.wrapDateLine(this.maxExtent, wrappingOptions);
                              
        }
        return bounds;
    },

    CLASS_NAME: "OpenLayers.Layer"
});
/* ======================================================================
    OpenLayers/Layer/HTTPRequest.js
   ====================================================================== */

/* Copyright (c) 2006-2013 by OpenLayers Contributors (see authors.txt for
 * full list of contributors). Published under the 2-clause BSD license.
 * See license.txt in the OpenLayers distribution or repository for the
 * full text of the license. */


/**
 * @requires OpenLayers/Layer.js
 */

/**
 * Class: OpenLayers.Layer.HTTPRequest
 * 
 * Inherits from: 
 *  - <OpenLayers.Layer>
 */
OpenLayers.Layer.HTTPRequest = OpenLayers.Class(OpenLayers.Layer, {

    /** 
     * Constant: URL_HASH_FACTOR
     * {Float} Used to hash URL param strings for multi-WMS server selection.
     *         Set to the Golden Ratio per Knuth's recommendation.
     */
    URL_HASH_FACTOR: (Math.sqrt(5) - 1) / 2,

    /** 
     * Property: url
     * {Array(String) or String} This is either an array of url strings or 
     *                           a single url string. 
     */
    url: null,

    /** 
     * Property: params
     * {Object} Hashtable of key/value parameters
     */
    params: null,
    
    /** 
     * APIProperty: reproject
     * *Deprecated*. See http://docs.openlayers.org/library/spherical_mercator.html
     * for information on the replacement for this functionality. 
     * {Boolean} Whether layer should reproject itself based on base layer 
     *           locations. This allows reprojection onto commercial layers. 
     *           Default is false: Most layers can't reproject, but layers 
     *           which can create non-square geographic pixels can, like WMS.
     *           
     */
    reproject: false,

    /**
     * Constructor: OpenLayers.Layer.HTTPRequest
     * 
     * Parameters:
     * name - {String}
     * url - {Array(String) or String}
     * params - {Object}
     * options - {Object} Hashtable of extra options to tag onto the layer
     */
    initialize: function(name, url, params, options) {
        OpenLayers.Layer.prototype.initialize.apply(this, [name, options]);
        this.url = url;
        if (!this.params) {
            this.params = OpenLayers.Util.extend({}, params);
        }
    },

    /**
     * APIMethod: destroy
     */
    destroy: function() {
        this.url = null;
        this.params = null;
        OpenLayers.Layer.prototype.destroy.apply(this, arguments); 
    },
    
    /**
     * APIMethod: clone
     * 
     * Parameters:
     * obj - {Object}
     * 
     * Returns:
     * {<OpenLayers.Layer.HTTPRequest>} An exact clone of this 
     *                                  <OpenLayers.Layer.HTTPRequest>
     */
    clone: function (obj) {
        
        if (obj == null) {
            obj = new OpenLayers.Layer.HTTPRequest(this.name,
                                                   this.url,
                                                   this.params,
                                                   this.getOptions());
        }
        
        //get all additions from superclasses
        obj = OpenLayers.Layer.prototype.clone.apply(this, [obj]);

        // copy/set any non-init, non-simple values here
        
        return obj;
    },

    /** 
     * APIMethod: setUrl
     * 
     * Parameters:
     * newUrl - {String}
     */
    setUrl: function(newUrl) {
        this.url = newUrl;
    },

    /**
     * APIMethod: mergeNewParams
     * 
     * Parameters:
     * newParams - {Object}
     *
     * Returns:
     * redrawn: {Boolean} whether the layer was actually redrawn.
     */
    mergeNewParams:function(newParams) {
        this.params = OpenLayers.Util.extend(this.params, newParams);
        var ret = this.redraw();
        if(this.map != null) {
            this.map.events.triggerEvent("changelayer", {
                layer: this,
                property: "params"
            });
        }
        return ret;
    },

    /**
     * APIMethod: redraw
     * Redraws the layer.  Returns true if the layer was redrawn, false if not.
     *
     * Parameters:
     * force - {Boolean} Force redraw by adding random parameter.
     *
     * Returns:
     * {Boolean} The layer was redrawn.
     */
    redraw: function(force) { 
        if (force) {
            return this.mergeNewParams({"_olSalt": Math.random()});
        } else {
            return OpenLayers.Layer.prototype.redraw.apply(this, []);
        }
    },
    
    /**
     * Method: selectUrl
     * selectUrl() implements the standard floating-point multiplicative
     *     hash function described by Knuth, and hashes the contents of the 
     *     given param string into a float between 0 and 1. This float is then
     *     scaled to the size of the provided urls array, and used to select
     *     a URL.
     *
     * Parameters:
     * paramString - {String}
     * urls - {Array(String)}
     * 
     * Returns:
     * {String} An entry from the urls array, deterministically selected based
     *          on the paramString.
     */
    selectUrl: function(paramString, urls) {
        var product = 1;
        for (var i=0, len=paramString.length; i<len; i++) { 
            product *= paramString.charCodeAt(i) * this.URL_HASH_FACTOR; 
            product -= Math.floor(product); 
        }
        return urls[Math.floor(product * urls.length)];
    },

    /** 
     * Method: getFullRequestString
     * Combine url with layer's params and these newParams. 
     *   
     *    does checking on the serverPath variable, allowing for cases when it 
     *     is supplied with trailing ? or &, as well as cases where not. 
     *
     *    return in formatted string like this:
     *        "server?key1=value1&key2=value2&key3=value3"
     * 
     * WARNING: The altUrl parameter is deprecated and will be removed in 3.0.
     *
     * Parameters:
     * newParams - {Object}
     * altUrl - {String} Use this as the url instead of the layer's url
     *   
     * Returns: 
     * {String}
     */
    getFullRequestString:function(newParams, altUrl) {

        // if not altUrl passed in, use layer's url
        var url = altUrl || this.url;
        
        // create a new params hashtable with all the layer params and the 
        // new params together. then convert to string
        var allParams = OpenLayers.Util.extend({}, this.params);
        allParams = OpenLayers.Util.extend(allParams, newParams);
        var paramsString = OpenLayers.Util.getParameterString(allParams);
        
        // if url is not a string, it should be an array of strings, 
        // in which case we will deterministically select one of them in 
        // order to evenly distribute requests to different urls.
        //
        if (OpenLayers.Util.isArray(url)) {
            url = this.selectUrl(paramsString, url);
        }   
 
        // ignore parameters that are already in the url search string
        var urlParams = 
            OpenLayers.Util.upperCaseObject(OpenLayers.Util.getParameters(url));
        for(var key in allParams) {
            if(key.toUpperCase() in urlParams) {
                delete allParams[key];
            }
        }
        paramsString = OpenLayers.Util.getParameterString(allParams);
        
        return OpenLayers.Util.urlAppend(url, paramsString);
    },

    CLASS_NAME: "OpenLayers.Layer.HTTPRequest"
});
/* ======================================================================
    OpenLayers/Tile.js
   ====================================================================== */

/* Copyright (c) 2006-2013 by OpenLayers Contributors (see authors.txt for
 * full list of contributors). Published under the 2-clause BSD license.
 * See license.txt in the OpenLayers distribution or repository for the
 * full text of the license. */


/**
 * @requires OpenLayers/BaseTypes/Class.js
 * @requires OpenLayers/Util.js
 */

/**
 * Class: OpenLayers.Tile 
 * This is a class designed to designate a single tile, however
 *     it is explicitly designed to do relatively little. Tiles store 
 *     information about themselves -- such as the URL that they are related
 *     to, and their size - but do not add themselves to the layer div 
 *     automatically, for example. Create a new tile with the 
 *     <OpenLayers.Tile> constructor, or a subclass. 
 * 
 * TBD 3.0 - remove reference to url in above paragraph
 * 
 */
OpenLayers.Tile = OpenLayers.Class({
    
    /**
     * APIProperty: events
     * {<OpenLayers.Events>} An events object that handles all 
     *     events on the tile.
     *
     * Register a listener for a particular event with the following syntax:
     * (code)
     * tile.events.register(type, obj, listener);
     * (end)
     *
     * Supported event types:
     * beforedraw - Triggered before the tile is drawn. Used to defer
     *     drawing to an animation queue. To defer drawing, listeners need
     *     to return false, which will abort drawing. The queue handler needs
     *     to call <draw>(true) to actually draw the tile.
     * loadstart - Triggered when tile loading starts.
     * loadend - Triggered when tile loading ends.
     * loaderror - Triggered before the loadend event (i.e. when the tile is
     *     still hidden) if the tile could not be loaded.
     * reload - Triggered when an already loading tile is reloaded.
     * unload - Triggered before a tile is unloaded.
     */
    events: null,

    /**
     * APIProperty: eventListeners
     * {Object} If set as an option at construction, the eventListeners
     *     object will be registered with <OpenLayers.Events.on>.  Object
     *     structure must be a listeners object as shown in the example for
     *     the events.on method.
     *
     * This options can be set in the ``tileOptions`` option from
     * <OpenLayers.Layer.Grid>. For example, to be notified of the
     * ``loadend`` event of each tiles:
     * (code)
     * new OpenLayers.Layer.OSM('osm', 'http://tile.openstreetmap.org/${z}/${x}/${y}.png', {
     *     tileOptions: {
     *         eventListeners: {
     *             'loadend': function(evt) {
     *                 // do something on loadend
     *             }
     *         }
     *     }
     * });
     * (end)
     */
    eventListeners: null,

    /**
     * Property: id 
     * {String} null
     */
    id: null,
    
    /** 
     * Property: layer 
     * {<OpenLayers.Layer>} layer the tile is attached to 
     */
    layer: null,
    
    /**
     * Property: url
     * {String} url of the request.
     *
     * TBD 3.0 
     * Deprecated. The base tile class does not need an url. This should be 
     * handled in subclasses. Does not belong here.
     */
    url: null,

    /** 
     * APIProperty: bounds 
     * {<OpenLayers.Bounds>} null
     */
    bounds: null,
    
    /** 
     * Property: size 
     * {<OpenLayers.Size>} null
     */
    size: null,
    
    /** 
     * Property: position 
     * {<OpenLayers.Pixel>} Top Left pixel of the tile
     */    
    position: null,
    
    /**
     * Property: isLoading
     * {Boolean} Is the tile loading?
     */
    isLoading: false,
    
    /** TBD 3.0 -- remove 'url' from the list of parameters to the constructor.
     *             there is no need for the base tile class to have a url.
     */

    /** 
     * Constructor: OpenLayers.Tile
     * Constructor for a new <OpenLayers.Tile> instance.
     * 
     * Parameters:
     * layer - {<OpenLayers.Layer>} layer that the tile will go in.
     * position - {<OpenLayers.Pixel>}
     * bounds - {<OpenLayers.Bounds>}
     * url - {<String>}
     * size - {<OpenLayers.Size>}
     * options - {Object}
     */   
    initialize: function(layer, position, bounds, url, size, options) {
        this.layer = layer;
        this.position = position.clone();
        this.setBounds(bounds);
        this.url = url;
        if (size) {
            this.size = size.clone();
        }

        //give the tile a unique id based on its BBOX.
        this.id = OpenLayers.Util.createUniqueID("Tile_");

        OpenLayers.Util.extend(this, options);

        this.events = new OpenLayers.Events(this);
        if (this.eventListeners instanceof Object) {
            this.events.on(this.eventListeners);
        }
    },

    /**
     * Method: unload
     * Call immediately before destroying if you are listening to tile
     * events, so that counters are properly handled if tile is still
     * loading at destroy-time. Will only fire an event if the tile is
     * still loading.
     */
    unload: function() {
       if (this.isLoading) { 
           this.isLoading = false; 
           this.events.triggerEvent("unload"); 
       }
    },
    
    /** 
     * APIMethod: destroy
     * Nullify references to prevent circular references and memory leaks.
     */
    destroy:function() {
        this.layer  = null;
        this.bounds = null;
        this.size = null;
        this.position = null;
        
        if (this.eventListeners) {
            this.events.un(this.eventListeners);
        }
        this.events.destroy();
        this.eventListeners = null;
        this.events = null;
    },
    
    /**
     * Method: draw
     * Clear whatever is currently in the tile, then return whether or not 
     *     it should actually be re-drawn. This is an example implementation
     *     that can be overridden by subclasses. The minimum thing to do here
     *     is to call <clear> and return the result from <shouldDraw>.
     *
     * Parameters:
     * force - {Boolean} If true, the tile will not be cleared and no beforedraw
     *     event will be fired. This is used for drawing tiles asynchronously
     *     after drawing has been cancelled by returning false from a beforedraw
     *     listener.
     * 
     * Returns:
     * {Boolean} Whether or not the tile should actually be drawn. Returns null
     *     if a beforedraw listener returned false.
     */
    draw: function(force) {
        if (!force) {
            //clear tile's contents and mark as not drawn
            this.clear();
        }
        var draw = this.shouldDraw();
        if (draw && !force && this.events.triggerEvent("beforedraw") === false) {
            draw = null;
        }
        return draw;
    },
    
    /**
     * Method: shouldDraw
     * Return whether or not the tile should actually be (re-)drawn. The only
     * case where we *wouldn't* want to draw the tile is if the tile is outside
     * its layer's maxExtent
     * 
     * Returns:
     * {Boolean} Whether or not the tile should actually be drawn.
     */
    shouldDraw: function() {        
        var withinMaxExtent = false,
            maxExtent = this.layer.maxExtent;
        if (maxExtent) {
            var map = this.layer.map;
            var worldBounds = map.baseLayer.wrapDateLine && map.getMaxExtent();
            if (this.bounds.intersectsBounds(maxExtent, {inclusive: false, worldBounds: worldBounds})) {
                withinMaxExtent = true;
            }
        }
        
        return withinMaxExtent || this.layer.displayOutsideMaxExtent;
    },
    
    /**
     * Method: setBounds
     * Sets the bounds on this instance
     *
     * Parameters:
     * bounds {<OpenLayers.Bounds>}
     */
    setBounds: function(bounds) {
        bounds = bounds.clone();
        if (this.layer.map.baseLayer.wrapDateLine) {
            var worldExtent = this.layer.map.getMaxExtent(),
                tolerance = this.layer.map.getResolution();
            bounds = bounds.wrapDateLine(worldExtent, {
                leftTolerance: tolerance,
                rightTolerance: tolerance
            });
        }
        this.bounds = bounds;
    },
    
    /** 
     * Method: moveTo
     * Reposition the tile.
     *
     * Parameters:
     * bounds - {<OpenLayers.Bounds>}
     * position - {<OpenLayers.Pixel>}
     * redraw - {Boolean} Call draw method on tile after moving.
     *     Default is true
     */
    moveTo: function (bounds, position, redraw) {
        if (redraw == null) {
            redraw = true;
        }

        this.setBounds(bounds);
        this.position = position.clone();
        if (redraw) {
            this.draw();
        }
    },

    /** 
     * Method: clear
     * Clear the tile of any bounds/position-related data so that it can 
     *     be reused in a new location.
     */
    clear: function(draw) {
        // to be extended by subclasses
    },
    
    CLASS_NAME: "OpenLayers.Tile"
});
/* ======================================================================
    OpenLayers/Tile/Image.js
   ====================================================================== */

/* Copyright (c) 2006-2013 by OpenLayers Contributors (see authors.txt for
 * full list of contributors). Published under the 2-clause BSD license.
 * See license.txt in the OpenLayers distribution or repository for the
 * full text of the license. */


/**
 * @requires OpenLayers/Tile.js
 * @requires OpenLayers/Animation.js
 * @requires OpenLayers/Util.js
 */

/**
 * Class: OpenLayers.Tile.Image
 * Instances of OpenLayers.Tile.Image are used to manage the image tiles
 * used by various layers.  Create a new image tile with the
 * <OpenLayers.Tile.Image> constructor.
 *
 * Inherits from:
 *  - <OpenLayers.Tile>
 */
OpenLayers.Tile.Image = OpenLayers.Class(OpenLayers.Tile, {

    /**
     * APIProperty: events
     * {<OpenLayers.Events>} An events object that handles all 
     *     events on the tile.
     *
     * Register a listener for a particular event with the following syntax:
     * (code)
     * tile.events.register(type, obj, listener);
     * (end)
     *
     * Supported event types (in addition to the <OpenLayers.Tile> events):
     * beforeload - Triggered before an image is prepared for loading, when the
     *     url for the image is known already. Listeners may call <setImage> on
     *     the tile instance. If they do so, that image will be used and no new
     *     one will be created.
     */

    /** 
     * APIProperty: url
     * {String} The URL of the image being requested. No default. Filled in by
     * layer.getURL() function. May be modified by loadstart listeners.
     */
    url: null,
    
    /** 
     * Property: imgDiv
     * {HTMLImageElement} The image for this tile.
     */
    imgDiv: null,
    
    /**
     * Property: frame
     * {DOMElement} The image element is appended to the frame.  Any gutter on
     * the image will be hidden behind the frame. If no gutter is set,
     * this will be null.
     */ 
    frame: null, 

    /** 
     * Property: imageReloadAttempts
     * {Integer} Attempts to load the image.
     */
    imageReloadAttempts: null,
    
    /**
     * Property: layerAlphaHack
     * {Boolean} True if the png alpha hack needs to be applied on the layer's div.
     */
    layerAlphaHack: null,
    
    /**
     * Property: asyncRequestId
     * {Integer} ID of an request to see if request is still valid. This is a
     * number which increments by 1 for each asynchronous request.
     */
    asyncRequestId: null,
    
    /**
     * APIProperty: maxGetUrlLength
     * {Number} If set, requests that would result in GET urls with more
     * characters than the number provided will be made using form-encoded
     * HTTP POST. It is good practice to avoid urls that are longer than 2048
     * characters.
     *
     * Caution:
     * Older versions of Gecko based browsers (e.g. Firefox < 3.5) and most
     * Opera versions do not fully support this option. On all browsers,
     * transition effects are not supported if POST requests are used.
     */
    maxGetUrlLength: null,

    /**
     * Property: canvasContext
     * {CanvasRenderingContext2D} A canvas context associated with
     * the tile image.
     */
    canvasContext: null,
    
    /**
     * APIProperty: crossOriginKeyword
     * The value of the crossorigin keyword to use when loading images. This is
     * only relevant when using <getCanvasContext> for tiles from remote
     * origins and should be set to either 'anonymous' or 'use-credentials'
     * for servers that send Access-Control-Allow-Origin headers with their
     * tiles.
     */
    crossOriginKeyword: null,

    /** TBD 3.0 - reorder the parameters to the init function to remove 
     *             URL. the getUrl() function on the layer gets called on 
     *             each draw(), so no need to specify it here.
     */

    /** 
     * Constructor: OpenLayers.Tile.Image
     * Constructor for a new <OpenLayers.Tile.Image> instance.
     * 
     * Parameters:
     * layer - {<OpenLayers.Layer>} layer that the tile will go in.
     * position - {<OpenLayers.Pixel>}
     * bounds - {<OpenLayers.Bounds>}
     * url - {<String>} Deprecated. Remove me in 3.0.
     * size - {<OpenLayers.Size>}
     * options - {Object}
     */   
    initialize: function(layer, position, bounds, url, size, options) {
        OpenLayers.Tile.prototype.initialize.apply(this, arguments);

        this.url = url; //deprecated remove me
        
        this.layerAlphaHack = this.layer.alpha && OpenLayers.Util.alphaHack();

        if (this.maxGetUrlLength != null || this.layer.gutter || this.layerAlphaHack) {
            // only create frame if it's needed
            this.frame = document.createElement("div");
            this.frame.style.position = "absolute";
            this.frame.style.overflow = "hidden";
        }
        if (this.maxGetUrlLength != null) {
            OpenLayers.Util.extend(this, OpenLayers.Tile.Image.IFrame);
        }
    },
    
    /** 
     * APIMethod: destroy
     * nullify references to prevent circular references and memory leaks
     */
    destroy: function() {
        if (this.imgDiv)  {
            this.clear();
            this.imgDiv = null;
            this.frame = null;
        }
        // don't handle async requests any more
        this.asyncRequestId = null;
        OpenLayers.Tile.prototype.destroy.apply(this, arguments);
    },
    
    /**
     * Method: draw
     * Check that a tile should be drawn, and draw it.
     * 
     * Returns:
     * {Boolean} Was a tile drawn? Or null if a beforedraw listener returned
     *     false.
     */
    draw: function() {
        var shouldDraw = OpenLayers.Tile.prototype.draw.apply(this, arguments);
        if (shouldDraw) {
            // The layer's reproject option is deprecated.
            if (this.layer != this.layer.map.baseLayer && this.layer.reproject) {
                // getBoundsFromBaseLayer is defined in deprecated.js.
                this.bounds = this.getBoundsFromBaseLayer(this.position);
            }
            if (this.isLoading) {
                //if we're already loading, send 'reload' instead of 'loadstart'.
                this._loadEvent = "reload";
            } else {
                this.isLoading = true;
                this._loadEvent = "loadstart";
            }
            this.renderTile();
            this.positionTile();
        } else if (shouldDraw === false) {
            this.unload();
        }
        return shouldDraw;
    },
    
    /**
     * Method: renderTile
     * Internal function to actually initialize the image tile,
     *     position it correctly, and set its url.
     */
    renderTile: function() {
        if (this.layer.async) {
            // Asynchronous image requests call the asynchronous getURL method
            // on the layer to fetch an image that covers 'this.bounds'.
            var id = this.asyncRequestId = (this.asyncRequestId || 0) + 1;
            this.layer.getURLasync(this.bounds, function(url) {
                if (id == this.asyncRequestId) {
                    this.url = url;
                    this.initImage();
                }
            }, this);
        } else {
            // synchronous image requests get the url immediately.
            this.url = this.layer.getURL(this.bounds);
            this.initImage();
        }
    },

    /**
     * Method: positionTile
     * Using the properties currenty set on the layer, position the tile correctly.
     * This method is used both by the async and non-async versions of the Tile.Image
     * code.
     */
    positionTile: function() {
        var style = this.getTile().style,
            size = this.frame ? this.size :
                this.layer.getImageSize(this.bounds),
            ratio = 1;
        if (this.layer instanceof OpenLayers.Layer.Grid) {
            ratio = this.layer.getServerResolution() / this.layer.map.getResolution();
        }
        style.left = this.position.x + "px";
        style.top = this.position.y + "px";
        style.width = Math.round(ratio * size.w) + "px";
        style.height = Math.round(ratio * size.h) + "px";
    },

    /** 
     * Method: clear
     * Remove the tile from the DOM, clear it of any image related data so that
     * it can be reused in a new location.
     */
    clear: function() {
        OpenLayers.Tile.prototype.clear.apply(this, arguments);
        var img = this.imgDiv;
        if (img) {
            var tile = this.getTile();
            if (tile.parentNode === this.layer.div) {
                this.layer.div.removeChild(tile);
            }
            this.setImgSrc();
            if (this.layerAlphaHack === true) {
                img.style.filter = "";
            }
            OpenLayers.Element.removeClass(img, "olImageLoadError");
        }
        this.canvasContext = null;
    },
    
    /**
     * Method: getImage
     * Returns or creates and returns the tile image.
     */
    getImage: function() {
        if (!this.imgDiv) {
            this.imgDiv = OpenLayers.Tile.Image.IMAGE.cloneNode(false);

            var style = this.imgDiv.style;
            if (this.frame) {
                var left = 0, top = 0;
                if (this.layer.gutter) {
                    left = this.layer.gutter / this.layer.tileSize.w * 100;
                    top = this.layer.gutter / this.layer.tileSize.h * 100;
                }
                style.left = -left + "%";
                style.top = -top + "%";
                style.width = (2 * left + 100) + "%";
                style.height = (2 * top + 100) + "%";
            }
            style.visibility = "hidden";
            style.opacity = 0;
            if (this.layer.opacity < 1) {
                style.filter = 'alpha(opacity=' +
                               (this.layer.opacity * 100) +
                               ')';
            }
            style.position = "absolute";
            if (this.layerAlphaHack) {
                // move the image out of sight
                style.paddingTop = style.height;
                style.height = "0";
                style.width = "100%";
            }
            if (this.frame) {
                this.frame.appendChild(this.imgDiv);
            }
        }

        return this.imgDiv;
    },
    
    /**
     * APIMethod: setImage
     * Sets the image element for this tile. This method should only be called
     * from beforeload listeners.
     *
     * Parameters
     * img - {HTMLImageElement} The image to use for this tile.
     */
    setImage: function(img) {
        this.imgDiv = img;
    },

    /**
     * Method: initImage
     * Creates the content for the frame on the tile.
     */
    initImage: function() {
        if (!this.url && !this.imgDiv) {
            // fast path out - if there is no tile url and no previous image
            this.isLoading = false;
            return;
        }
        this.events.triggerEvent('beforeload');
        this.layer.div.appendChild(this.getTile());
        this.events.triggerEvent(this._loadEvent);
        var img = this.getImage();
        var src = img.getAttribute('src') || '';
        if (this.url && OpenLayers.Util.isEquivalentUrl(src, this.url)) {
            this._loadTimeout = window.setTimeout(
                OpenLayers.Function.bind(this.onImageLoad, this), 0
            );
        } else {
            this.stopLoading();
            if (this.crossOriginKeyword) {
                img.removeAttribute("crossorigin");
            }
            OpenLayers.Event.observe(img, "load",
                OpenLayers.Function.bind(this.onImageLoad, this)
            );
            OpenLayers.Event.observe(img, "error",
                OpenLayers.Function.bind(this.onImageError, this)
            );
            this.imageReloadAttempts = 0;
            this.setImgSrc(this.url);
        }
    },
    
    /**
     * Method: setImgSrc
     * Sets the source for the tile image
     *
     * Parameters:
     * url - {String} or undefined to hide the image
     */
    setImgSrc: function(url) {
        var img = this.imgDiv;
        if (url) {
            img.style.visibility = 'hidden';
            img.style.opacity = 0;
            // don't set crossOrigin if the url is a data URL
            if (this.crossOriginKeyword) {
                if (url.substr(0, 5) !== 'data:') {
                    img.setAttribute("crossorigin", this.crossOriginKeyword);
                } else {
                    img.removeAttribute("crossorigin");
                }
            }
            img.src = url;
        } else {
            // Remove reference to the image, and leave it to the browser's
            // caching and garbage collection.
            this.stopLoading();
            this.imgDiv = null;
            if (img.parentNode) {
                img.parentNode.removeChild(img);
            }
        }
    },
    
    /**
     * Method: getTile
     * Get the tile's markup.
     *
     * Returns:
     * {DOMElement} The tile's markup
     */
    getTile: function() {
        return this.frame ? this.frame : this.getImage();
    },

    /**
     * Method: createBackBuffer
     * Create a backbuffer for this tile. A backbuffer isn't exactly a clone
     * of the tile's markup, because we want to avoid the reloading of the
     * image. So we clone the frame, and steal the image from the tile.
     *
     * Returns:
     * {DOMElement} The markup, or undefined if the tile has no image
     * or if it's currently loading.
     */
    createBackBuffer: function() {
        if (!this.imgDiv || this.isLoading) {
            return;
        }
        var backBuffer;
        if (this.frame) {
            backBuffer = this.frame.cloneNode(false);
            backBuffer.appendChild(this.imgDiv);
        } else {
            backBuffer = this.imgDiv;
        }
        this.imgDiv = null;
        return backBuffer;
    },

    /**
     * Method: onImageLoad
     * Handler for the image onload event
     */
    onImageLoad: function() {
        var img = this.imgDiv;
        this.stopLoading();
        img.style.visibility = 'inherit';
        img.style.opacity = this.layer.opacity;
        this.isLoading = false;
        this.canvasContext = null;
        this.events.triggerEvent("loadend");

        if (this.layerAlphaHack === true) {
            img.style.filter =
                "progid:DXImageTransform.Microsoft.AlphaImageLoader(src='" +
                img.src + "', sizingMethod='scale')";
        }
    },
    
    /**
     * Method: onImageError
     * Handler for the image onerror event
     */
    onImageError: function() {
        var img = this.imgDiv;
        if (img.src != null) {
            this.imageReloadAttempts++;
            if (this.imageReloadAttempts <= OpenLayers.IMAGE_RELOAD_ATTEMPTS) {
                this.setImgSrc(this.layer.getURL(this.bounds));
            } else {
                OpenLayers.Element.addClass(img, "olImageLoadError");
                this.events.triggerEvent("loaderror");
                this.onImageLoad();
            }
        }
    },
    
    /**
     * Method: stopLoading
     * Stops a loading sequence so <onImageLoad> won't be executed.
     */
    stopLoading: function() {
        OpenLayers.Event.stopObservingElement(this.imgDiv);
        window.clearTimeout(this._loadTimeout);
        delete this._loadTimeout;
    },

    /**
     * APIMethod: getCanvasContext
     * Returns a canvas context associated with the tile image (with
     * the image drawn on it).
     * Returns undefined if the browser does not support canvas, if
     * the tile has no image or if it's currently loading.
     *
     * The function returns a canvas context instance but the
     * underlying canvas is still available in the 'canvas' property:
     * (code)
     * var context = tile.getCanvasContext();
     * if (context) {
     *     var data = context.canvas.toDataURL('image/jpeg');
     * }
     * (end)
     *
     * Returns:
     * {Boolean}
     */
    getCanvasContext: function() {
        if (OpenLayers.CANVAS_SUPPORTED && this.imgDiv && !this.isLoading) {
            if (!this.canvasContext) {
                var canvas = document.createElement("canvas");
                canvas.width = this.size.w;
                canvas.height = this.size.h;
                this.canvasContext = canvas.getContext("2d");
                this.canvasContext.drawImage(this.imgDiv, 0, 0);
            }
            return this.canvasContext;
        }
    },

    CLASS_NAME: "OpenLayers.Tile.Image"

});

/** 
 * Constant: OpenLayers.Tile.Image.IMAGE
 * {HTMLImageElement} The image for a tile.
 */
OpenLayers.Tile.Image.IMAGE = (function() {
    var img = new Image();
    img.className = "olTileImage";
    // avoid image gallery menu in IE6
    img.galleryImg = "no";
    return img;
}());

/* ======================================================================
    OpenLayers/Layer/Grid.js
   ====================================================================== */

/* Copyright (c) 2006-2013 by OpenLayers Contributors (see authors.txt for
 * full list of contributors). Published under the 2-clause BSD license.
 * See license.txt in the OpenLayers distribution or repository for the
 * full text of the license. */


/**
 * @requires OpenLayers/Layer/HTTPRequest.js
 * @requires OpenLayers/Tile/Image.js
 */

/**
 * Class: OpenLayers.Layer.Grid
 * Base class for layers that use a lattice of tiles.  Create a new grid
 * layer with the <OpenLayers.Layer.Grid> constructor.
 *
 * Inherits from:
 *  - <OpenLayers.Layer.HTTPRequest>
 */
OpenLayers.Layer.Grid = OpenLayers.Class(OpenLayers.Layer.HTTPRequest, {
    
    /**
     * APIProperty: tileSize
     * {<OpenLayers.Size>}
     */
    tileSize: null,

    /**
     * Property: tileOriginCorner
     * {String} If the <tileOrigin> property is not provided, the tile origin 
     *     will be derived from the layer's <maxExtent>.  The corner of the 
     *     <maxExtent> used is determined by this property.  Acceptable values
     *     are "tl" (top left), "tr" (top right), "bl" (bottom left), and "br"
     *     (bottom right).  Default is "bl".
     */
    tileOriginCorner: "bl",
    
    /**
     * APIProperty: tileOrigin
     * {<OpenLayers.LonLat>} Optional origin for aligning the grid of tiles.
     *     If provided, requests for tiles at all resolutions will be aligned
     *     with this location (no tiles shall overlap this location).  If
     *     not provided, the grid of tiles will be aligned with the layer's
     *     <maxExtent>.  Default is ``null``.
     */
    tileOrigin: null,
    
    /** APIProperty: tileOptions
     *  {Object} optional configuration options for <OpenLayers.Tile> instances
     *  created by this Layer, if supported by the tile class.
     */
    tileOptions: null,

    /**
     * APIProperty: tileClass
     * {<OpenLayers.Tile>} The tile class to use for this layer.
     *     Defaults is OpenLayers.Tile.Image.
     */
    tileClass: OpenLayers.Tile.Image,
    
    /**
     * Property: grid
     * {Array(Array(<OpenLayers.Tile>))} This is an array of rows, each row is 
     *     an array of tiles.
     */
    grid: null,

    /**
     * APIProperty: singleTile
     * {Boolean} Moves the layer into single-tile mode, meaning that one tile 
     *     will be loaded. The tile's size will be determined by the 'ratio'
     *     property. When the tile is dragged such that it does not cover the 
     *     entire viewport, it is reloaded.
     */
    singleTile: false,

    /** APIProperty: ratio
     *  {Float} Used only when in single-tile mode, this specifies the 
     *          ratio of the size of the single tile to the size of the map.
     *          Default value is 1.5.
     */
    ratio: 1.5,

    /**
     * APIProperty: buffer
     * {Integer} Used only when in gridded mode, this specifies the number of 
     *           extra rows and colums of tiles on each side which will
     *           surround the minimum grid tiles to cover the map.
     *           For very slow loading layers, a larger value may increase
     *           performance somewhat when dragging, but will increase bandwidth
     *           use significantly. 
     */
    buffer: 0,

    /**
     * APIProperty: transitionEffect
     * {String} The transition effect to use when the map is zoomed.
     * Two posible values:
     *
     * "resize" - Existing tiles are resized on zoom to provide a visual
     *     effect of the zoom having taken place immediately.  As the
     *     new tiles become available, they are drawn on top of the
     *     resized tiles (this is the default setting).
     * "map-resize" - Existing tiles are resized on zoom and placed below the
     *     base layer.  New tiles for the base layer will cover existing tiles.
     *     This setting is recommended when having an overlay duplicated during
     *     the transition is undesirable (e.g. street labels or big transparent
     *     fills). 
     * null - No transition effect.
     *
     * Using "resize" on non-opaque layers can cause undesired visual
     * effects.  Set transitionEffect to null in this case.
     */
    transitionEffect: "resize",

    /**
     * APIProperty: numLoadingTiles
     * {Integer} How many tiles are still loading?
     */
    numLoadingTiles: 0,

    /**
     * Property: serverResolutions
     * {Array(Number}} This property is documented in subclasses as
     *     an API property.
     */
    serverResolutions: null,

    /**
     * Property: loading
     * {Boolean} Indicates if tiles are being loaded.
     */
    loading: false,
    
    /**
     * Property: backBuffer
     * {DOMElement} The back buffer.
     */
    backBuffer: null,

    /**
     * Property: gridResolution
     * {Number} The resolution of the current grid. Used for backbuffer and
     *     client zoom. This property is updated every time the grid is
     *     initialized.
     */
    gridResolution: null,

    /**
     * Property: backBufferResolution
     * {Number} The resolution of the current back buffer. This property is
     *     updated each time a back buffer is created.
     */
    backBufferResolution: null,

    /**
     * Property: backBufferLonLat
     * {Object} The top-left corner of the current back buffer. Includes lon
     *     and lat properties. This object is updated each time a back buffer
     *     is created.
     */
    backBufferLonLat: null,

    /**
     * Property: backBufferTimerId
     * {Number} The id of the back buffer timer. This timer is used to
     *     delay the removal of the back buffer, thereby preventing
     *     flash effects caused by tile animation.
     */
    backBufferTimerId: null,

    /**
     * APIProperty: removeBackBufferDelay
     * {Number} Delay for removing the backbuffer when all tiles have finished
     *     loading. Can be set to 0 when no css opacity transitions for the
     *     olTileImage class are used. Default is 0 for <singleTile> layers,
     *     2500 for tiled layers. See <className> for more information on
     *     tile animation.
     */
    removeBackBufferDelay: null,

    /**
     * APIProperty: className
     * {String} Name of the class added to the layer div. If not set in the
     *     options passed to the constructor then className defaults to
     *     "olLayerGridSingleTile" for single tile layers (see <singleTile>),
     *     and "olLayerGrid" for non single tile layers.
     *
     * Note:
     *
     * The displaying of tiles is not animated by default for single tile
     *     layers - OpenLayers' default theme (style.css) includes this:
     * (code)
     * .olLayerGrid .olTileImage {
     *     -webkit-transition: opacity 0.2s linear;
     *     -moz-transition: opacity 0.2s linear;
     *     -o-transition: opacity 0.2s linear;
     *     transition: opacity 0.2s linear;
     *  }
     * (end)
     * To animate tile displaying for any grid layer the following
     *     CSS rule can be used:
     * (code)
     * .olTileImage {
     *     -webkit-transition: opacity 0.2s linear;
     *     -moz-transition: opacity 0.2s linear;
     *     -o-transition: opacity 0.2s linear;
     *     transition: opacity 0.2s linear;
     * }
     * (end)
     * In that case, to avoid flash effects, <removeBackBufferDelay>
     *     should not be zero.
     */
    className: null,
    
    /**
     * Register a listener for a particular event with the following syntax:
     * (code)
     * layer.events.register(type, obj, listener);
     * (end)
     *
     * Listeners will be called with a reference to an event object.  The
     *     properties of this event depends on exactly what happened.
     *
     * All event objects have at least the following properties:
     * object - {Object} A reference to layer.events.object.
     * element - {DOMElement} A reference to layer.events.element.
     *
     * Supported event types:
     * addtile - Triggered when a tile is added to this layer. Listeners receive
     *     an object as first argument, which has a tile property that
     *     references the tile that has been added.
     * tileloadstart - Triggered when a tile starts loading. Listeners receive
     *     an object as first argument, which has a tile property that
     *     references the tile that starts loading.
     * tileloaded - Triggered when each new tile is
     *     loaded, as a means of progress update to listeners.
     *     listeners can access 'numLoadingTiles' if they wish to keep
     *     track of the loading progress. Listeners are called with an object
     *     with a 'tile' property as first argument, making the loaded tile
     *     available to the listener, and an 'aborted' property, which will be
     *     true when loading was aborted and no tile data is available.
     * tileerror - Triggered before the tileloaded event (i.e. when the tile is
     *     still hidden) if a tile failed to load. Listeners receive an object
     *     as first argument, which has a tile property that references the
     *     tile that could not be loaded.
     * retile - Triggered when the layer recreates its tile grid.
     */

    /**
     * Property: gridLayout
     * {Object} Object containing properties tilelon, tilelat, startcol,
     * startrow
     */
    gridLayout: null,
    
    /**
     * Property: rowSign
     * {Number} 1 for grids starting at the top, -1 for grids starting at the
     * bottom. This is used for several grid index and offset calculations.
     */
    rowSign: null,

    /**
     * Property: transitionendEvents
     * {Array} Event names for transitionend
     */
    transitionendEvents: [
        'transitionend', 'webkitTransitionEnd', 'otransitionend',
        'oTransitionEnd'
    ],

    /**
     * Constructor: OpenLayers.Layer.Grid
     * Create a new grid layer
     *
     * Parameters:
     * name - {String}
     * url - {String}
     * params - {Object}
     * options - {Object} Hashtable of extra options to tag onto the layer
     */
    initialize: function(name, url, params, options) {
        OpenLayers.Layer.HTTPRequest.prototype.initialize.apply(this, 
                                                                arguments);
        this.grid = [];
        this._removeBackBuffer = OpenLayers.Function.bind(this.removeBackBuffer, this);

        this.initProperties();

        this.rowSign = this.tileOriginCorner.substr(0, 1) === "t" ? 1 : -1;
    },

    /**
     * Method: initProperties
     * Set any properties that depend on the value of singleTile.
     * Currently sets removeBackBufferDelay and className
     */
    initProperties: function() {
        if (this.options.removeBackBufferDelay === undefined) {
            this.removeBackBufferDelay = this.singleTile ? 0 : 2500;
        }

        if (this.options.className === undefined) {
            this.className = this.singleTile ? 'olLayerGridSingleTile' :
                                               'olLayerGrid';
        }
    },

    /**
     * Method: setMap
     *
     * Parameters:
     * map - {<OpenLayers.Map>} The map.
     */
    setMap: function(map) {
        OpenLayers.Layer.HTTPRequest.prototype.setMap.call(this, map);
        OpenLayers.Element.addClass(this.div, this.className);
    },

    /**
     * Method: removeMap
     * Called when the layer is removed from the map.
     *
     * Parameters:
     * map - {<OpenLayers.Map>} The map.
     */
    removeMap: function(map) {
        this.removeBackBuffer();
    },

    /**
     * APIMethod: destroy
     * Deconstruct the layer and clear the grid.
     */
    destroy: function() {
        this.removeBackBuffer();
        this.clearGrid();

        this.grid = null;
        this.tileSize = null;
        OpenLayers.Layer.HTTPRequest.prototype.destroy.apply(this, arguments); 
    },

    /**
     * APIMethod: mergeNewParams
     * Refetches tiles with new params merged, keeping a backbuffer. Each
     * loading new tile will have a css class of '.olTileReplacing'. If a
     * stylesheet applies a 'display: none' style to that class, any fade-in
     * transition will not apply, and backbuffers for each tile will be removed
     * as soon as the tile is loaded.
     * 
     * Parameters:
     * newParams - {Object}
     *
     * Returns:
     * redrawn: {Boolean} whether the layer was actually redrawn.
     */

    /**
     * Method: clearGrid
     * Go through and remove all tiles from the grid, calling
     *    destroy() on each of them to kill circular references
     */
    clearGrid:function() {
        if (this.grid) {
            for(var iRow=0, len=this.grid.length; iRow<len; iRow++) {
                var row = this.grid[iRow];
                for(var iCol=0, clen=row.length; iCol<clen; iCol++) {
                    var tile = row[iCol];
                    this.destroyTile(tile);
                }
            }
            this.grid = [];
            this.gridResolution = null;
            this.gridLayout = null;
        }
    },

   /**
    * APIMethod: addOptions
    * 
    * Parameters:
    * newOptions - {Object}
    * reinitialize - {Boolean} If set to true, and if resolution options of the
    *     current baseLayer were changed, the map will be recentered to make
    *     sure that it is displayed with a valid resolution, and a
    *     changebaselayer event will be triggered.
    */
    addOptions: function (newOptions, reinitialize) {
        var singleTileChanged = newOptions.singleTile !== undefined && 
            newOptions.singleTile !== this.singleTile;
        OpenLayers.Layer.HTTPRequest.prototype.addOptions.apply(this, arguments);
        if (this.map && singleTileChanged) {
            this.initProperties();
            this.clearGrid();
            this.tileSize = this.options.tileSize;
            this.setTileSize();
            this.moveTo(null, true);
        }
    },
    
    /**
     * APIMethod: clone
     * Create a clone of this layer
     *
     * Parameters:
     * obj - {Object} Is this ever used?
     * 
     * Returns:
     * {<OpenLayers.Layer.Grid>} An exact clone of this OpenLayers.Layer.Grid
     */
    clone: function (obj) {
        
        if (obj == null) {
            obj = new OpenLayers.Layer.Grid(this.name,
                                            this.url,
                                            this.params,
                                            this.getOptions());
        }

        //get all additions from superclasses
        obj = OpenLayers.Layer.HTTPRequest.prototype.clone.apply(this, [obj]);

        // copy/set any non-init, non-simple values here
        if (this.tileSize != null) {
            obj.tileSize = this.tileSize.clone();
        }
        
        // we do not want to copy reference to grid, so we make a new array
        obj.grid = [];
        obj.gridResolution = null;
        // same for backbuffer
        obj.backBuffer = null;
        obj.backBufferTimerId = null;
        obj.loading = false;
        obj.numLoadingTiles = 0;

        return obj;
    },    

    /**
     * Method: moveTo
     * This function is called whenever the map is moved. All the moving
     * of actual 'tiles' is done by the map, but moveTo's role is to accept
     * a bounds and make sure the data that that bounds requires is pre-loaded.
     *
     * Parameters:
     * bounds - {<OpenLayers.Bounds>}
     * zoomChanged - {Boolean}
     * dragging - {Boolean}
     */
    moveTo:function(bounds, zoomChanged, dragging) {

        OpenLayers.Layer.HTTPRequest.prototype.moveTo.apply(this, arguments);

        bounds = bounds || this.map.getExtent();

        if (bounds != null) {
             
            // if grid is empty or zoom has changed, we *must* re-tile
            var forceReTile = !this.grid.length || zoomChanged;
            
            // total bounds of the tiles
            var tilesBounds = this.getTilesBounds();            

            // the new map resolution
            var resolution = this.map.getResolution();

            // the server-supported resolution for the new map resolution
            var serverResolution = this.getServerResolution(resolution);

            if (this.singleTile) {
                
                // We want to redraw whenever even the slightest part of the 
                //  current bounds is not contained by our tile.
                //  (thus, we do not specify partial -- its default is false)

                if ( forceReTile ||
                     (!dragging && !tilesBounds.containsBounds(bounds))) {

                    // In single tile mode with no transition effect, we insert
                    // a non-scaled backbuffer when the layer is moved. But if
                    // a zoom occurs right after a move, i.e. before the new
                    // image is received, we need to remove the backbuffer, or
                    // an ill-positioned image will be visible during the zoom
                    // transition.

                    if(zoomChanged && this.transitionEffect !== 'resize') {
                        this.removeBackBuffer();
                    }

                    if(!zoomChanged || this.transitionEffect === 'resize') {
                        this.applyBackBuffer(resolution);
                    }

                    this.initSingleTile(bounds);
                }
            } else {

                // if the bounds have changed such that they are not even 
                // *partially* contained by our tiles (e.g. when user has 
                // programmatically panned to the other side of the earth on
                // zoom level 18), then moveGriddedTiles could potentially have
                // to run through thousands of cycles, so we want to reTile
                // instead (thus, partial true).  
                forceReTile = forceReTile ||
                    !tilesBounds.intersectsBounds(bounds, {
                        worldBounds: this.map.baseLayer.wrapDateLine &&
                            this.map.getMaxExtent()
                    });

                if(forceReTile) {
                    if(zoomChanged && (this.transitionEffect === 'resize' ||
                                          this.gridResolution === resolution)) {
                        this.applyBackBuffer(resolution);
                    }
                    this.initGriddedTiles(bounds);
                } else {
                    this.moveGriddedTiles();
                }
            }
        }
    },

    /**
     * Method: getTileData
     * Given a map location, retrieve a tile and the pixel offset within that
     *     tile corresponding to the location.  If there is not an existing 
     *     tile in the grid that covers the given location, null will be 
     *     returned.
     *
     * Parameters:
     * loc - {<OpenLayers.LonLat>} map location
     *
     * Returns:
     * {Object} Object with the following properties: tile ({<OpenLayers.Tile>}),
     *     i ({Number} x-pixel offset from top left), and j ({Integer} y-pixel
     *     offset from top left).
     */
    getTileData: function(loc) {
        var data = null,
            x = loc.lon,
            y = loc.lat,
            numRows = this.grid.length;

        if (this.map && numRows) {
            var res = this.map.getResolution(),
                tileWidth = this.tileSize.w,
                tileHeight = this.tileSize.h,
                bounds = this.grid[0][0].bounds,
                left = bounds.left,
                top = bounds.top;

            if (x < left) {
                // deal with multiple worlds
                if (this.map.baseLayer.wrapDateLine) {
                    var worldWidth = this.map.getMaxExtent().getWidth();
                    var worldsAway = Math.ceil((left - x) / worldWidth);
                    x += worldWidth * worldsAway;
                }
            }
            // tile distance to location (fractional number of tiles);
            var dtx = (x - left) / (res * tileWidth);
            var dty = (top - y) / (res * tileHeight);
            // index of tile in grid
            var col = Math.floor(dtx);
            var row = Math.floor(dty);
            if (row >= 0 && row < numRows) {
                var tile = this.grid[row][col];
                if (tile) {
                    data = {
                        tile: tile,
                        // pixel index within tile
                        i: Math.floor((dtx - col) * tileWidth),
                        j: Math.floor((dty - row) * tileHeight)
                    };                    
                }
            }
        }
        return data;
    },
    
    /**
     * Method: destroyTile
     *
     * Parameters:
     * tile - {<OpenLayers.Tile>}
     */
    destroyTile: function(tile) {
        this.removeTileMonitoringHooks(tile);
        tile.destroy();
    },

    /**
     * Method: getServerResolution
     * Return the closest server-supported resolution.
     *
     * Parameters:
     * resolution - {Number} The base resolution. If undefined the
     *     map resolution is used.
     *
     * Returns:
     * {Number} The closest server resolution value.
     */
    getServerResolution: function(resolution) {
        var distance = Number.POSITIVE_INFINITY;
        resolution = resolution || this.map.getResolution();
        if(this.serverResolutions &&
           OpenLayers.Util.indexOf(this.serverResolutions, resolution) === -1) {
            var i, newDistance, newResolution, serverResolution;
            for(i=this.serverResolutions.length-1; i>= 0; i--) {
                newResolution = this.serverResolutions[i];
                newDistance = Math.abs(newResolution - resolution);
                if (newDistance > distance) {
                    break;
                }
                distance = newDistance;
                serverResolution = newResolution;
            }
            resolution = serverResolution;
        }
        return resolution;
    },

    /**
     * Method: getServerZoom
     * Return the zoom value corresponding to the best matching server
     * resolution, taking into account <serverResolutions> and <zoomOffset>.
     *
     * Returns:
     * {Number} The closest server supported zoom. This is not the map zoom
     *     level, but an index of the server's resolutions array.
     */
    getServerZoom: function() {
        var resolution = this.getServerResolution();
        return this.serverResolutions ?
            OpenLayers.Util.indexOf(this.serverResolutions, resolution) :
            this.map.getZoomForResolution(resolution) + (this.zoomOffset || 0);
    },

    /**
     * Method: applyBackBuffer
     * Create, insert, scale and position a back buffer for the layer.
     *
     * Parameters:
     * resolution - {Number} The resolution to transition to.
     */
    applyBackBuffer: function(resolution) {
        if(this.backBufferTimerId !== null) {
            this.removeBackBuffer();
        }
        var backBuffer = this.backBuffer;
        if(!backBuffer) {
            backBuffer = this.createBackBuffer();
            if(!backBuffer) {
                return;
            }
            if (resolution === this.gridResolution) {
                this.div.insertBefore(backBuffer, this.div.firstChild);
            } else {
                this.map.baseLayer.div.parentNode.insertBefore(backBuffer, this.map.baseLayer.div);
            }
            this.backBuffer = backBuffer;

            // set some information in the instance for subsequent
            // calls to applyBackBuffer where the same back buffer
            // is reused
            var topLeftTileBounds = this.grid[0][0].bounds;
            this.backBufferLonLat = {
                lon: topLeftTileBounds.left,
                lat: topLeftTileBounds.top
            };
            this.backBufferResolution = this.gridResolution;
        }
        
        var ratio = this.backBufferResolution / resolution;

        // scale the tiles inside the back buffer
        var tiles = backBuffer.childNodes, tile;
        for (var i=tiles.length-1; i>=0; --i) {
            tile = tiles[i];
            tile.style.top = ((ratio * tile._i * tile._h) | 0) + 'px';
            tile.style.left = ((ratio * tile._j * tile._w) | 0) + 'px';
            tile.style.width = Math.round(ratio * tile._w) + 'px';
            tile.style.height = Math.round(ratio * tile._h) + 'px';
        }

        // and position it (based on the grid's top-left corner)
        var position = this.getViewPortPxFromLonLat(
                this.backBufferLonLat, resolution);
        var leftOffset = this.map.layerContainerOriginPx.x;
        var topOffset = this.map.layerContainerOriginPx.y;
        backBuffer.style.left = Math.round(position.x - leftOffset) + 'px';
        backBuffer.style.top = Math.round(position.y - topOffset) + 'px';
    },

    /**
     * Method: createBackBuffer
     * Create a back buffer.
     *
     * Returns:
     * {DOMElement} The DOM element for the back buffer, undefined if the
     * grid isn't initialized yet.
     */
    createBackBuffer: function() {
        var backBuffer;
        if(this.grid.length > 0) {
            backBuffer = document.createElement('div');
            backBuffer.id = this.div.id + '_bb';
            backBuffer.className = 'olBackBuffer';
            backBuffer.style.position = 'absolute';
            var map = this.map;
            backBuffer.style.zIndex = this.transitionEffect === 'resize' ?
                    this.getZIndex() - 1 :
                    // 'map-resize':
                    map.Z_INDEX_BASE.BaseLayer -
                            (map.getNumLayers() - map.getLayerIndex(this));
            for(var i=0, lenI=this.grid.length; i<lenI; i++) {
                for(var j=0, lenJ=this.grid[i].length; j<lenJ; j++) {
                    var tile = this.grid[i][j],
                        markup = this.grid[i][j].createBackBuffer();
                    if (markup) {
                        markup._i = i;
                        markup._j = j;
                        markup._w = tile.size.w;
                        markup._h = tile.size.h;
                        markup.id = tile.id + '_bb';
                        backBuffer.appendChild(markup);
                    }
                }
            }
        }
        return backBuffer;
    },

    /**
     * Method: removeBackBuffer
     * Remove back buffer from DOM.
     */
    removeBackBuffer: function() {
        if (this._transitionElement) {
            for (var i=this.transitionendEvents.length-1; i>=0; --i) {
                OpenLayers.Event.stopObserving(this._transitionElement,
                    this.transitionendEvents[i], this._removeBackBuffer);
            }
            delete this._transitionElement;
        }
        if(this.backBuffer) {
            if (this.backBuffer.parentNode) {
                this.backBuffer.parentNode.removeChild(this.backBuffer);
            }
            this.backBuffer = null;
            this.backBufferResolution = null;
            if(this.backBufferTimerId !== null) {
                window.clearTimeout(this.backBufferTimerId);
                this.backBufferTimerId = null;
            }
        }
    },

    /**
     * Method: moveByPx
     * Move the layer based on pixel vector.
     *
     * Parameters:
     * dx - {Number}
     * dy - {Number}
     */
    moveByPx: function(dx, dy) {
        if (!this.singleTile) {
            this.moveGriddedTiles();
        }
    },

    /**
     * APIMethod: setTileSize
     * Check if we are in singleTile mode and if so, set the size as a ratio
     *     of the map size (as specified by the layer's 'ratio' property).
     * 
     * Parameters:
     * size - {<OpenLayers.Size>}
     */
    setTileSize: function(size) { 
        if (this.singleTile) {
            size = this.map.getSize();
            size.h = parseInt(size.h * this.ratio, 10);
            size.w = parseInt(size.w * this.ratio, 10);
        } 
        OpenLayers.Layer.HTTPRequest.prototype.setTileSize.apply(this, [size]);
    },

    /**
     * APIMethod: getTilesBounds
     * Return the bounds of the tile grid.
     *
     * Returns:
     * {<OpenLayers.Bounds>} A Bounds object representing the bounds of all the
     *     currently loaded tiles (including those partially or not at all seen 
     *     onscreen).
     */
    getTilesBounds: function() {    
        var bounds = null; 
        
        var length = this.grid.length;
        if (length) {
            var bottomLeftTileBounds = this.grid[length - 1][0].bounds,
                width = this.grid[0].length * bottomLeftTileBounds.getWidth(),
                height = this.grid.length * bottomLeftTileBounds.getHeight();
            
            bounds = new OpenLayers.Bounds(bottomLeftTileBounds.left, 
                                           bottomLeftTileBounds.bottom,
                                           bottomLeftTileBounds.left + width, 
                                           bottomLeftTileBounds.bottom + height);
        }   
        return bounds;
    },

    /**
     * Method: initSingleTile
     * 
     * Parameters: 
     * bounds - {<OpenLayers.Bounds>}
     */
    initSingleTile: function(bounds) {
        this.events.triggerEvent("retile");

        //determine new tile bounds
        var center = bounds.getCenterLonLat();
        var tileWidth = bounds.getWidth() * this.ratio;
        var tileHeight = bounds.getHeight() * this.ratio;
                                       
        var tileBounds = 
            new OpenLayers.Bounds(center.lon - (tileWidth/2),
                                  center.lat - (tileHeight/2),
                                  center.lon + (tileWidth/2),
                                  center.lat + (tileHeight/2));
  
        var px = this.map.getLayerPxFromLonLat({
            lon: tileBounds.left,
            lat: tileBounds.top
        });

        if (!this.grid.length) {
            this.grid[0] = [];
        }

        var tile = this.grid[0][0];
        if (!tile) {
            tile = this.addTile(tileBounds, px);
            
            this.addTileMonitoringHooks(tile);
            tile.draw();
            this.grid[0][0] = tile;
        } else {
            tile.moveTo(tileBounds, px);
        }           
        
        //remove all but our single tile
        this.removeExcessTiles(1,1);

        // store the resolution of the grid
        this.gridResolution = this.getServerResolution();
    },

    /** 
     * Method: calculateGridLayout
     * Generate parameters for the grid layout.
     *
     * Parameters:
     * bounds - {<OpenLayers.Bound>|Object} OpenLayers.Bounds or an
     *     object with a 'left' and 'top' properties.
     * origin - {<OpenLayers.LonLat>|Object} OpenLayers.LonLat or an
     *     object with a 'lon' and 'lat' properties.
     * resolution - {Number}
     *
     * Returns:
     * {Object} Object containing properties tilelon, tilelat, startcol,
     * startrow
     */
    calculateGridLayout: function(bounds, origin, resolution) {
        var tilelon = resolution * this.tileSize.w;
        var tilelat = resolution * this.tileSize.h;
        
        var offsetlon = bounds.left - origin.lon;
        var tilecol = Math.floor(offsetlon/tilelon) - this.buffer;
        
        var rowSign = this.rowSign;

        var offsetlat = rowSign * (origin.lat - bounds.top + tilelat);  
        var tilerow = Math[~rowSign ? 'floor' : 'ceil'](offsetlat/tilelat) - this.buffer * rowSign;
        
        return { 
          tilelon: tilelon, tilelat: tilelat,
          startcol: tilecol, startrow: tilerow
        };

    },
    
    /**
     * Method: getTileOrigin
     * Determine the origin for aligning the grid of tiles.  If a <tileOrigin>
     *     property is supplied, that will be returned.  Otherwise, the origin
     *     will be derived from the layer's <maxExtent> property.  In this case,
     *     the tile origin will be the corner of the <maxExtent> given by the 
     *     <tileOriginCorner> property.
     *
     * Returns:
     * {<OpenLayers.LonLat>} The tile origin.
     */
    getTileOrigin: function() {
        var origin = this.tileOrigin;
        if (!origin) {
            var extent = this.getMaxExtent();
            var edges = ({
                "tl": ["left", "top"],
                "tr": ["right", "top"],
                "bl": ["left", "bottom"],
                "br": ["right", "bottom"]
            })[this.tileOriginCorner];
            origin = new OpenLayers.LonLat(extent[edges[0]], extent[edges[1]]);
        }
        return origin;
    },

    /**
     * Method: getTileBoundsForGridIndex
     *
     * Parameters:
     * row - {Number} The row of the grid
     * col - {Number} The column of the grid
     *
     * Returns:
     * {<OpenLayers.Bounds>} The bounds for the tile at (row, col)
     */
    getTileBoundsForGridIndex: function(row, col) {
        var origin = this.getTileOrigin();
        var tileLayout = this.gridLayout;
        var tilelon = tileLayout.tilelon;
        var tilelat = tileLayout.tilelat;
        var startcol = tileLayout.startcol;
        var startrow = tileLayout.startrow;
        var rowSign = this.rowSign;
        return new OpenLayers.Bounds(
            origin.lon + (startcol + col) * tilelon,
            origin.lat - (startrow + row * rowSign) * tilelat * rowSign,
            origin.lon + (startcol + col + 1) * tilelon,
            origin.lat - (startrow + (row - 1) * rowSign) * tilelat * rowSign
        );
    },

    /**
     * Method: initGriddedTiles
     * 
     * Parameters:
     * bounds - {<OpenLayers.Bounds>}
     */
    initGriddedTiles:function(bounds) {
        this.events.triggerEvent("retile");

        // work out mininum number of rows and columns; this is the number of
        // tiles required to cover the viewport plus at least one for panning

        var viewSize = this.map.getSize();
        
        var origin = this.getTileOrigin();
        var resolution = this.map.getResolution(),
            serverResolution = this.getServerResolution(),
            ratio = resolution / serverResolution,
            tileSize = {
                w: this.tileSize.w / ratio,
                h: this.tileSize.h / ratio
            };

        var minRows = Math.ceil(viewSize.h/tileSize.h) + 
                      2 * this.buffer + 1;
        var minCols = Math.ceil(viewSize.w/tileSize.w) +
                      2 * this.buffer + 1;

        var tileLayout = this.calculateGridLayout(bounds, origin, serverResolution);
        this.gridLayout = tileLayout;
        
        var tilelon = tileLayout.tilelon;
        var tilelat = tileLayout.tilelat;
        
        var layerContainerDivLeft = this.map.layerContainerOriginPx.x;
        var layerContainerDivTop = this.map.layerContainerOriginPx.y;

        var tileBounds = this.getTileBoundsForGridIndex(0, 0);
        var startPx = this.map.getViewPortPxFromLonLat(
            new OpenLayers.LonLat(tileBounds.left, tileBounds.top)
        );
        startPx.x = Math.round(startPx.x) - layerContainerDivLeft;
        startPx.y = Math.round(startPx.y) - layerContainerDivTop;

        var tileData = [], center = this.map.getCenter();

        var rowidx = 0;
        do {
            var row = this.grid[rowidx];
            if (!row) {
                row = [];
                this.grid.push(row);
            }
            
            var colidx = 0;
            do {
                tileBounds = this.getTileBoundsForGridIndex(rowidx, colidx);
                var px = startPx.clone();
                px.x = px.x + colidx * Math.round(tileSize.w);
                px.y = px.y + rowidx * Math.round(tileSize.h);
                var tile = row[colidx];
                if (!tile) {
                    tile = this.addTile(tileBounds, px);
                    this.addTileMonitoringHooks(tile);
                    row.push(tile);
                } else {
                    tile.moveTo(tileBounds, px, false);
                }
                var tileCenter = tileBounds.getCenterLonLat();
                tileData.push({
                    tile: tile,
                    distance: Math.pow(tileCenter.lon - center.lon, 2) +
                        Math.pow(tileCenter.lat - center.lat, 2)
                });
     
                colidx += 1;
            } while ((tileBounds.right <= bounds.right + tilelon * this.buffer)
                     || colidx < minCols);
             
            rowidx += 1;
        } while((tileBounds.bottom >= bounds.bottom - tilelat * this.buffer)
                || rowidx < minRows);
        
        //shave off exceess rows and colums
        this.removeExcessTiles(rowidx, colidx);

        var resolution = this.getServerResolution();
        // store the resolution of the grid
        this.gridResolution = resolution;

        //now actually draw the tiles
        tileData.sort(function(a, b) {
            return a.distance - b.distance; 
        });
        for (var i=0, ii=tileData.length; i<ii; ++i) {
            tileData[i].tile.draw();
        }
    },

    /**
     * Method: getMaxExtent
     * Get this layer's maximum extent. (Implemented as a getter for
     *     potential specific implementations in sub-classes.)
     *
     * Returns:
     * {<OpenLayers.Bounds>}
     */
    getMaxExtent: function() {
        return this.maxExtent;
    },
    
    /**
     * APIMethod: addTile
     * Create a tile, initialize it, and add it to the layer div. 
     *
     * Parameters
     * bounds - {<OpenLayers.Bounds>}
     * position - {<OpenLayers.Pixel>}
     *
     * Returns:
     * {<OpenLayers.Tile>} The added OpenLayers.Tile
     */
    addTile: function(bounds, position) {
        var tile = new this.tileClass(
            this, position, bounds, null, this.tileSize, this.tileOptions
        );
        this.events.triggerEvent("addtile", {tile: tile});
        return tile;
    },
    
    /** 
     * Method: addTileMonitoringHooks
     * This function takes a tile as input and adds the appropriate hooks to 
     *     the tile so that the layer can keep track of the loading tiles.
     * 
     * Parameters: 
     * tile - {<OpenLayers.Tile>}
     */
    addTileMonitoringHooks: function(tile) {
        
        var replacingCls = 'olTileReplacing';

        tile.onLoadStart = function() {
            //if that was first tile then trigger a 'loadstart' on the layer
            if (this.loading === false) {
                this.loading = true;
                this.events.triggerEvent("loadstart");
            }
            this.events.triggerEvent("tileloadstart", {tile: tile});
            this.numLoadingTiles++;
            if (!this.singleTile && this.backBuffer && this.gridResolution === this.backBufferResolution) {
                OpenLayers.Element.addClass(tile.getTile(), replacingCls);
            }
        };
      
        tile.onLoadEnd = function(evt) {
            this.numLoadingTiles--;
            var aborted = evt.type === 'unload';
            this.events.triggerEvent("tileloaded", {
                tile: tile,
                aborted: aborted
            });
            if (!this.singleTile && !aborted && this.backBuffer && this.gridResolution === this.backBufferResolution) {
                var tileDiv = tile.getTile();
                if (OpenLayers.Element.getStyle(tileDiv, 'display') === 'none') {
                    var bufferTile = document.getElementById(tile.id + '_bb');
                    if (bufferTile) {
                        bufferTile.parentNode.removeChild(bufferTile);
                    }
                }
                OpenLayers.Element.removeClass(tileDiv, replacingCls);
            }
            //if that was the last tile, then trigger a 'loadend' on the layer
            if (this.numLoadingTiles === 0) {
                if (this.backBuffer) {
                    if (this.backBuffer.childNodes.length === 0) {
                        // no tiles transitioning, remove immediately
                        this.removeBackBuffer();
                    } else {
                        // wait until transition has ended or delay has passed
                        this._transitionElement = aborted ?
                            this.div.lastChild : tile.imgDiv;
                        var transitionendEvents = this.transitionendEvents;
                        for (var i=transitionendEvents.length-1; i>=0; --i) {
                            OpenLayers.Event.observe(this._transitionElement,
                                transitionendEvents[i],
                                this._removeBackBuffer);
                        }
                        // the removal of the back buffer is delayed to prevent
                        // flash effects due to the animation of tile displaying
                        this.backBufferTimerId = window.setTimeout(
                            this._removeBackBuffer, this.removeBackBufferDelay
                        );
                    }
                }
                this.loading = false;
                this.events.triggerEvent("loadend");
            }
        };
        
        tile.onLoadError = function() {
            this.events.triggerEvent("tileerror", {tile: tile});
        };
        
        tile.events.on({
            "loadstart": tile.onLoadStart,
            "loadend": tile.onLoadEnd,
            "unload": tile.onLoadEnd,
            "loaderror": tile.onLoadError,
            scope: this
        });
    },

    /** 
     * Method: removeTileMonitoringHooks
     * This function takes a tile as input and removes the tile hooks 
     *     that were added in addTileMonitoringHooks()
     * 
     * Parameters: 
     * tile - {<OpenLayers.Tile>}
     */
    removeTileMonitoringHooks: function(tile) {
        tile.unload();
        tile.events.un({
            "loadstart": tile.onLoadStart,
            "loadend": tile.onLoadEnd,
            "unload": tile.onLoadEnd,
            "loaderror": tile.onLoadError,
            scope: this
        });
    },
    
    /**
     * Method: moveGriddedTiles
     */
    moveGriddedTiles: function() {
        var buffer = this.buffer + 1;
        while(true) {
            var tlTile = this.grid[0][0];
            var tlViewPort = {
                x: tlTile.position.x +
                    this.map.layerContainerOriginPx.x,
                y: tlTile.position.y +
                    this.map.layerContainerOriginPx.y
            };
            var ratio = this.getServerResolution() / this.map.getResolution();
            var tileSize = {
                w: Math.round(this.tileSize.w * ratio),
                h: Math.round(this.tileSize.h * ratio)
            };
            if (tlViewPort.x > -tileSize.w * (buffer - 1)) {
                this.shiftColumn(true, tileSize);
            } else if (tlViewPort.x < -tileSize.w * buffer) {
                this.shiftColumn(false, tileSize);
            } else if (tlViewPort.y > -tileSize.h * (buffer - 1)) {
                this.shiftRow(true, tileSize);
            } else if (tlViewPort.y < -tileSize.h * buffer) {
                this.shiftRow(false, tileSize);
            } else {
                break;
            }
        }
    },

    /**
     * Method: shiftRow
     * Shifty grid work
     *
     * Parameters:
     * prepend - {Boolean} if true, prepend to beginning.
     *                          if false, then append to end
     * tileSize - {Object} rendered tile size; object with w and h properties
     */
    shiftRow: function(prepend, tileSize) {
        var grid = this.grid;
        var rowIndex = prepend ? 0 : (grid.length - 1);
        var sign = prepend ? -1 : 1;
        var rowSign = this.rowSign;
        var tileLayout = this.gridLayout;
        tileLayout.startrow += sign * rowSign;

        var modelRow = grid[rowIndex];
        var row = grid[prepend ? 'pop' : 'shift']();
        for (var i=0, len=row.length; i<len; i++) {
            var tile = row[i];
            var position = modelRow[i].position.clone();
            position.y += tileSize.h * sign;
            tile.moveTo(this.getTileBoundsForGridIndex(rowIndex, i), position);
        }
        grid[prepend ? 'unshift' : 'push'](row);
    },

    /**
     * Method: shiftColumn
     * Shift grid work in the other dimension
     *
     * Parameters:
     * prepend - {Boolean} if true, prepend to beginning.
     *                          if false, then append to end
     * tileSize - {Object} rendered tile size; object with w and h properties
     */
    shiftColumn: function(prepend, tileSize) {
        var grid = this.grid;
        var colIndex = prepend ? 0 : (grid[0].length - 1);
        var sign = prepend ? -1 : 1;
        var tileLayout = this.gridLayout;
        tileLayout.startcol += sign;

        for (var i=0, len=grid.length; i<len; i++) {
            var row = grid[i];
            var position = row[colIndex].position.clone();
            var tile = row[prepend ? 'pop' : 'shift']();            
            position.x += tileSize.w * sign;
            tile.moveTo(this.getTileBoundsForGridIndex(i, colIndex), position);
            row[prepend ? 'unshift' : 'push'](tile);
        }
    },

    /**
     * Method: removeExcessTiles
     * When the size of the map or the buffer changes, we may need to
     *     remove some excess rows and columns.
     * 
     * Parameters:
     * rows - {Integer} Maximum number of rows we want our grid to have.
     * columns - {Integer} Maximum number of columns we want our grid to have.
     */
    removeExcessTiles: function(rows, columns) {
        var i, l;
        
        // remove extra rows
        while (this.grid.length > rows) {
            var row = this.grid.pop();
            for (i=0, l=row.length; i<l; i++) {
                var tile = row[i];
                this.destroyTile(tile);
            }
        }
        
        // remove extra columns
        for (i=0, l=this.grid.length; i<l; i++) {
            while (this.grid[i].length > columns) {
                var row = this.grid[i];
                var tile = row.pop();
                this.destroyTile(tile);
            }
        }
    },

    /**
     * Method: onMapResize
     * For singleTile layers, this will set a new tile size according to the
     * dimensions of the map pane.
     */
    onMapResize: function() {
        if (this.singleTile) {
            this.clearGrid();
            this.setTileSize();
        }
    },
    
    /**
     * APIMethod: getTileBounds
     * Returns The tile bounds for a layer given a pixel location.
     *
     * Parameters:
     * viewPortPx - {<OpenLayers.Pixel>} The location in the viewport.
     *
     * Returns:
     * {<OpenLayers.Bounds>} Bounds of the tile at the given pixel location.
     */
    getTileBounds: function(viewPortPx) {
        var maxExtent = this.maxExtent;
        var resolution = this.getResolution();
        var tileMapWidth = resolution * this.tileSize.w;
        var tileMapHeight = resolution * this.tileSize.h;
        var mapPoint = this.getLonLatFromViewPortPx(viewPortPx);
        var tileLeft = maxExtent.left + (tileMapWidth *
                                         Math.floor((mapPoint.lon -
                                                     maxExtent.left) /
                                                    tileMapWidth));
        var tileBottom = maxExtent.bottom + (tileMapHeight *
                                             Math.floor((mapPoint.lat -
                                                         maxExtent.bottom) /
                                                        tileMapHeight));
        return new OpenLayers.Bounds(tileLeft, tileBottom,
                                     tileLeft + tileMapWidth,
                                     tileBottom + tileMapHeight);
    },

    CLASS_NAME: "OpenLayers.Layer.Grid"
});
/* ======================================================================
    OpenLayers/Layer/WMS.js
   ====================================================================== */

/* Copyright (c) 2006-2013 by OpenLayers Contributors (see authors.txt for
 * full list of contributors). Published under the 2-clause BSD license.
 * See license.txt in the OpenLayers distribution or repository for the
 * full text of the license. */


/**
 * @requires OpenLayers/Layer/Grid.js
 */

/**
 * Class: OpenLayers.Layer.WMS
 * Instances of OpenLayers.Layer.WMS are used to display data from OGC Web
 *     Mapping Services. Create a new WMS layer with the <OpenLayers.Layer.WMS>
 *     constructor.
 * 
 * Inherits from:
 *  - <OpenLayers.Layer.Grid>
 */
OpenLayers.Layer.WMS = OpenLayers.Class(OpenLayers.Layer.Grid, {

    /**
     * Constant: DEFAULT_PARAMS
     * {Object} Hashtable of default parameter key/value pairs 
     */
    DEFAULT_PARAMS: { service: "WMS",
                      version: "1.1.1",
                      request: "GetMap",
                      styles: "",
                      format: "image/jpeg"
                     },
    
    /**
     * APIProperty: isBaseLayer
     * {Boolean} Default is true for WMS layer
     */
    isBaseLayer: true,
    
    /**
     * APIProperty: encodeBBOX
     * {Boolean} Should the BBOX commas be encoded? The WMS spec says 'no', 
     * but some services want it that way. Default false.
     */
    encodeBBOX: false,
    
    /** 
     * APIProperty: noMagic 
     * {Boolean} If true, the image format will not be automagicaly switched 
     *     from image/jpeg to image/png or image/gif when using 
     *     TRANSPARENT=TRUE. Also isBaseLayer will not changed by the  
     *     constructor. Default false. 
     */ 
    noMagic: false,
    
    /**
     * Property: yx
     * {Object} Keys in this object are EPSG codes for which the axis order
     *     is to be reversed (yx instead of xy, LatLon instead of LonLat), with
     *     true as value. This is only relevant for WMS versions >= 1.3.0, and
     *     only if yx is not set in <OpenLayers.Projection.defaults> for the
     *     used projection.
     */
    yx: {},
    
    /**
     * Constructor: OpenLayers.Layer.WMS
     * Create a new WMS layer object
     *
     * Examples:
     *
     * The code below creates a simple WMS layer using the image/jpeg format.
     * (code)
     * var wms = new OpenLayers.Layer.WMS("NASA Global Mosaic",
     *                                    "http://wms.jpl.nasa.gov/wms.cgi", 
     *                                    {layers: "modis,global_mosaic"});
     * (end)
     * Note the 3rd argument (params). Properties added to this object will be
     * added to the WMS GetMap requests used for this layer's tiles. The only
     * mandatory parameter is "layers". Other common WMS params include
     * "transparent", "styles" and "format". Note that the "srs" param will
     * always be ignored. Instead, it will be derived from the baseLayer's or
     * map's projection.
     *
     * The code below creates a transparent WMS layer with additional options.
     * (code)
     * var wms = new OpenLayers.Layer.WMS("NASA Global Mosaic",
     *                                    "http://wms.jpl.nasa.gov/wms.cgi", 
     *                                    {
     *                                        layers: "modis,global_mosaic",
     *                                        transparent: true
     *                                    }, {
     *                                        opacity: 0.5,
     *                                        singleTile: true
     *                                    });
     * (end)
     * Note that by default, a WMS layer is configured as baseLayer. Setting
     * the "transparent" param to true will apply some magic (see <noMagic>).
     * The default image format changes from image/jpeg to image/png, and the
     * layer is not configured as baseLayer.
     *
     * Parameters:
     * name - {String} A name for the layer
     * url - {String} Base url for the WMS
     *                (e.g. http://wms.jpl.nasa.gov/wms.cgi)
     * params - {Object} An object with key/value pairs representing the
     *                   GetMap query string parameters and parameter values.
     * options - {Object} Hashtable of extra options to tag onto the layer.
     *     These options include all properties listed above, plus the ones
     *     inherited from superclasses.
     */
    initialize: function(name, url, params, options) {
        var newArguments = [];
        //uppercase params
        params = OpenLayers.Util.upperCaseObject(params);
        if (parseFloat(params.VERSION) >= 1.3 && !params.EXCEPTIONS) {
            params.EXCEPTIONS = "INIMAGE";
        } 
        newArguments.push(name, url, params, options);
        OpenLayers.Layer.Grid.prototype.initialize.apply(this, newArguments);
        OpenLayers.Util.applyDefaults(
                       this.params, 
                       OpenLayers.Util.upperCaseObject(this.DEFAULT_PARAMS)
                       );


        //layer is transparent        
        if (!this.noMagic && this.params.TRANSPARENT && 
            this.params.TRANSPARENT.toString().toLowerCase() == "true") {
            
            // unless explicitly set in options, make layer an overlay
            if ( (options == null) || (!options.isBaseLayer) ) {
                this.isBaseLayer = false;
            } 
            
            // jpegs can never be transparent, so intelligently switch the 
            //  format, depending on the browser's capabilities
            if (this.params.FORMAT == "image/jpeg") {
                this.params.FORMAT = OpenLayers.Util.alphaHack() ? "image/gif"
                                                                 : "image/png";
            }
        }

    },    

    /**
     * Method: clone
     * Create a clone of this layer
     *
     * Returns:
     * {<OpenLayers.Layer.WMS>} An exact clone of this layer
     */
    clone: function (obj) {
        
        if (obj == null) {
            obj = new OpenLayers.Layer.WMS(this.name,
                                           this.url,
                                           this.params,
                                           this.getOptions());
        }

        //get all additions from superclasses
        obj = OpenLayers.Layer.Grid.prototype.clone.apply(this, [obj]);

        // copy/set any non-init, non-simple values here

        return obj;
    },    
    
    /**
     * APIMethod: reverseAxisOrder
     * Returns true if the axis order is reversed for the WMS version and
     * projection of the layer.
     * 
     * Returns:
     * {Boolean} true if the axis order is reversed, false otherwise.
     */
    reverseAxisOrder: function() {
        var projCode = this.projection.getCode();
        return parseFloat(this.params.VERSION) >= 1.3 && 
            !!(this.yx[projCode] || (OpenLayers.Projection.defaults[projCode] && 
            OpenLayers.Projection.defaults[projCode].yx));
    },
    
    /**
     * Method: getURL
     * Return a GetMap query string for this layer
     *
     * Parameters:
     * bounds - {<OpenLayers.Bounds>} A bounds representing the bbox for the
     *                                request.
     *
     * Returns:
     * {String} A string with the layer's url and parameters and also the
     *          passed-in bounds and appropriate tile size specified as 
     *          parameters.
     */
    getURL: function (bounds) {
        bounds = this.adjustBounds(bounds);
        
        var imageSize = this.getImageSize();
        var newParams = {};
        // WMS 1.3 introduced axis order
        var reverseAxisOrder = this.reverseAxisOrder();
        newParams.BBOX = this.encodeBBOX ?
            bounds.toBBOX(null, reverseAxisOrder) :
            bounds.toArray(reverseAxisOrder);
        newParams.WIDTH = imageSize.w;
        newParams.HEIGHT = imageSize.h;
        var requestString = this.getFullRequestString(newParams);
        return requestString;
    },

    /**
     * APIMethod: mergeNewParams
     * Catch changeParams and uppercase the new params to be merged in
     *     before calling changeParams on the super class.
     * 
     *     Once params have been changed, the tiles will be reloaded with
     *     the new parameters.
     * 
     * Parameters:
     * newParams - {Object} Hashtable of new params to use
     */
    mergeNewParams:function(newParams) {
        var upperParams = OpenLayers.Util.upperCaseObject(newParams);
        var newArguments = [upperParams];
        return OpenLayers.Layer.Grid.prototype.mergeNewParams.apply(this, 
                                                             newArguments);
    },

    /** 
     * APIMethod: getFullRequestString
     * Combine the layer's url with its params and these newParams. 
     *   
     *     Add the SRS parameter from projection -- this is probably
     *     more eloquently done via a setProjection() method, but this 
     *     works for now and always.
     *
     * Parameters:
     * newParams - {Object}
     * altUrl - {String} Use this as the url instead of the layer's url
     * 
     * Returns:
     * {String} 
     */
    getFullRequestString:function(newParams, altUrl) {
        var mapProjection = this.map.getProjectionObject();
        var projectionCode = this.projection && this.projection.equals(mapProjection) ?
            this.projection.getCode() :
            mapProjection.getCode();
        var value = (projectionCode == "none") ? null : projectionCode;
        if (parseFloat(this.params.VERSION) >= 1.3) {
            this.params.CRS = value;
        } else {
            this.params.SRS = value;
        }
        
        if (typeof this.params.TRANSPARENT == "boolean") {
            newParams.TRANSPARENT = this.params.TRANSPARENT ? "TRUE" : "FALSE";
        }

        return OpenLayers.Layer.Grid.prototype.getFullRequestString.apply(
                                                    this, arguments);
    },

    CLASS_NAME: "OpenLayers.Layer.WMS"
});