/* 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($(this).attr("nodeName")=="#document"){
			if(window.location.search.search(strParamName) > -1 ){
				qString = window.location.search.substr(1,window.location.search.length).split("&");
			}
		}
		else if($(this).attr("href")!="undefined"){
			var strHref = $(this).attr("href");

			if( strHref.indexOf("?") > -1 ){
				var strQueryString = strHref.substr(strHref.indexOf("?")+1);
				qString = strQueryString.split("&");
			}
		}
		else 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{
			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;
	}
});