/* 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 = {};
	this.names='';
	this.names_arr=Array();
	this.qs='';
	this.qsadded;
	//alert('ok');
}

Querystring.prototype.StringToArray=function(){
	// Turn <plus> back to <space>
    // See: http://www.w3.org/TR/REC-html40/interact/forms.html#h-17.13.4.1
	this.qs = this.qs.replace(/\+/g, ' ');
	var args = this.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;
		this.names_arr[i]=name;
		//if(this.qsadded)alert(this.qsadded.names);
	}
	this.names=this.names_arr.join(',');
}

Querystring.prototype.update=function(qsupdate){
  	var qs2=(qsupdate)?'&'+qsupdate:'';
	if(qs2!=null)if (qs2.length == 0) return;

	this.qsadded=new Querystring();
	if(qsupdate){
	  this.qsadded.qs=qsupdate;
	  this.qsadded.StringToArray();
	  //alert(this.qsadded.params);
	}
	
	this.qs = location.search.substring(1, location.search.length);
	
	this.StringToArray();
	
	qsupdate=this.qsadded.names.split(',');
	for(var i=0;i<qsupdate.length;i++){
		//alert(this.qsadded.params[qsupdate[i]]);
	  if(this.qsadded.params[qsupdate[i]]){
		  this.params[qsupdate[i]]=this.qsadded.params[qsupdate[i]];
		  this.names_arr.union(this.qsadded.names_arr);
		  this.names=this.names_arr.join(',');
		  //alert(this.names);
	  }
	  //alert(qsupdate[i]);
	}
}

Querystring.prototype.ArrayToString=function(names,params){
  arr=names.split(',');
  var q_arr=Array();
  
  for (var i = 0; i < arr.length; i++) {
	  //alert(arr[i]);
      q_arr[i]=arr[i]+'='+params[arr[i]];
  }
  return q_arr.join('&');
}

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

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