/* Copyright (c) 2006-2007 Mathias Bank (http://www.mathias-bank.de)
* Dual licensed under the MIT (http://www.opensource.org/licenses/mit-license.php) 
* and GPL (http://www.opensource.org/licenses/gpl-license.php) licenses.
* 
* Version 2.1
* 
* Thanks to 
* Hinnerk Ruemenapf - http://hinnerk.ruemenapf.de/ for bug reporting and fixing.
* Tom Leonard for some improvements
* 
*/
jQuery.fn.extend({
    /**
    * Returns get parameters.
    *
    * If the desired param does not exist, null will be returned
    *
    * To get the document params:
    * @example value = $(document).getUrlParam("paramName");
    * 
    * To get the params of a html-attribut (uses src attribute)
    * @example value = $('#imgLink').getUrlParam("paramName");
    */
    getUrlParam: function (strParamName) {
        strParamName = escape(unescape(strParamName));

        var returnVal = new Array();
        var qString = null;

        if ($(this).attr("nodeName") == "#document") {
            //document-handler

            if (window.location.search.search(strParamName) > -1) {

                qString = window.location.search.substr(1, window.location.search.length).split("&");
            }

        } else if ($(this).attr("src") != "undefined") {

            var strHref = $(this).attr("src")
            if (strHref.indexOf("?") > -1) {
                var strQueryString = strHref.substr(strHref.indexOf("?") + 1);
                qString = strQueryString.split("&");
            }
        } else if ($(this).attr("href") != "undefined") {

            var strHref = $(this).attr("href")
            if (strHref.indexOf("?") > -1) {
                var strQueryString = strHref.substr(strHref.indexOf("?") + 1);
                qString = strQueryString.split("&");
            }
        } else {
            return null;
        }


        if (qString == null) return null;


        for (var i = 0; i < qString.length; i++) {
            if (escape(unescape(qString[i].split("=")[0])) == strParamName) {
                returnVal.push(qString[i].split("=")[1]);
            }

        }


        if (returnVal.length == 0) return null;
        else if (returnVal.length == 1) return returnVal[0];
        else return returnVal;
    }
});