/* Client-side access to querystring name=value pairs
	Version 1.3
	28 May 2008
	
	License (Simplified BSD):
	http://adamv.com/dev/javascript/qslicense.txt
*/
function Querystring(qs) { // optionally pass a querystring to parse
	this.params = {};
	
	if (qs == null) qs = location.search.substring(1, location.search.length);
	if (qs.length == 0) return;

	// Turn <plus> back to <space>
	// See: http://www.w3.org/TR/REC-html40/interact/forms.html#h-17.13.4.1
	qs = qs.replace(/\+/g, ' ');
	var args = qs.split('&'); // parse out name/value pairs separated via &
	
	// split out each name=value pair
	for (var i = 0; i < args.length; i++) {
		var pair = args[i].split('=');
		var name = decodeURIComponent(pair[0]);
		
		var value = (pair.length==2)
			? decodeURIComponent(pair[1])
			: name;
		
		this.params[name] = value;
	}
}

Querystring.prototype.get = function(key, default_) {
	var value = this.params[key];
	return (value != null) ? value : default_;
}

Querystring.prototype.contains = function(key) {
	var value = this.params[key];
	return (value != null);
}


function replaceQSParam(url, paramName, newValue) {
	// if no queryString is present, append a new query parameter
	if (url.indexOf('?') == -1)
		return (url+"?"+paramName+"="+UrlEncode(newValue)); //x.asp?Name=Peter+Paul
	else {
		// the query parameter does not already exist on the queryString
		if ( (url.indexOf("?"+paramName+"=") == -1 ) && (url.indexOf("&"+paramName+"=") == -1))	{
 			return (url+"&"+paramName+"="+UrlEncode(newValue)); //x.asp?Age=25&Name=Peter+Paul;
 		} else {
 			// query parameter already exists.  Replace the current value with the new value.
     		var replaceQSPrefix=(url.indexOf("?"+paramName+"=")==-1)?"&"+paramName+"=":"?"+paramName+"=";
     		var replaceQSSuffix=""; //This will be John in case of ?Name=John or &Name=John 
     		startpos=url.indexOf(replaceQSPrefix);

     		for (a=(startpos+replaceQSPrefix.length);a<url.length;a++) {
         		if (url.charAt(a)=='&') //Next querystring beginning
         			break;
         		else
         			replaceQSSuffix += url.charAt(a);
         	}
         	newUrl=url.replace(replaceQSPrefix+replaceQSSuffix,replaceQSPrefix+UrlEncode(newValue));
         	return newUrl;
   		}	
	}		
}

function UrlEncode(text) {		
	text=ReplaceAll(text, "?", "%3F");
	text=ReplaceAll(text, "=", "%3D");
	text=ReplaceAll(text, "&", "%26");
	text=ReplaceAll(text, " ", "+");
	text=ReplaceAll(text, ",", "%2c");	

	return text;
}

//Replace all given string from a string
function ReplaceAll(varb, replaceThis, replaceBy) {	
    	newvarbarray=varb.split(replaceThis);
    	newvarb=newvarbarray.join(replaceBy);	
    	return newvarb;
}