/* 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
 * 
 */
 
 /* Copyright (c) 2006 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.
 * 
 * Thanks to Hinnerk Ruemenapf - http://hinnerk.ruemenapf.de/ for bug reporting and fixing.
 */
 function URLEncode(unencodedValue )
{
	// The Javascript escape and unescape functions do not correspond
	// with what browsers actually do...
	var SAFECHARS = "0123456789" +					// Numeric
					"ABCDEFGHIJKLMNOPQRSTUVWXYZ" +	// Alphabetic
					"abcdefghijklmnopqrstuvwxyz" +
					"-_.!~*'()";					// RFC2396 Mark characters
	var HEX = "0123456789ABCDEF";

	var plaintext = unencodedValue;
	var encoded = "";
	for (var i = 0; i < plaintext.length; i++ ) {
		var ch = plaintext.charAt(i);
	    if (ch == " ") {
		    encoded += "+";				// x-www-urlencoded, rather than %20
		} else if (SAFECHARS.indexOf(ch) != -1) {
		    encoded += ch;
		} else {
		    var charCode = ch.charCodeAt(0);
			if (charCode > 255) {
			    alert( "Unicode Character '" 
                        + ch 
                        + "' cannot be encoded using standard URL encoding.\n" +
				          "(URL encoding only supports 8-bit characters.)\n" +
						  "A space (+) will be substituted." );
				encoded += "+";
			} else {
				encoded += "%";
				encoded += HEX.charAt((charCode >> 4) & 0xF);
				encoded += HEX.charAt(charCode & 0xF);
			}
		}
	} // for

	return encoded;
};

function URLDecode(encodedValue)
{
   // Replace + with ' '
   // Replace %xx with equivalent character
   // Put [ERROR] in output if %xx is invalid.
   var HEXCHARS = "0123456789ABCDEFabcdef"; 
   var encoded = encodedValue
   var plaintext = "";
   var i = 0;
   while (i < encoded.length) {
       var ch = encoded.charAt(i);
	   if (ch == "+") {
	       plaintext += " ";
		   i++;
	   } else if (ch == "%") {
			if (i < (encoded.length-2) 
					&& HEXCHARS.indexOf(encoded.charAt(i+1)) != -1 
					&& HEXCHARS.indexOf(encoded.charAt(i+2)) != -1 ) {
				plaintext += unescape( encoded.substr(i,3) );
				i += 3;
			} else {
				alert( 'Bad escape combination near ...' + encoded.substr(i) );
				plaintext += "%[ERROR]";
				i++;
			}
		} else {
		   plaintext += ch;
		   i++;
		}
	} // while
   return plaintext;
};


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 URLDecode(returnVal[0]);
	  else return URLDecode(returnVal);
	}
});