function Querystring(qs) { // optionally pass a querystring to parse
	this.params = new Object();
	this.get=Querystring_get;
	this.deleteQuery=Querystring_deleteQuery;
	this.getQueryString=Querystring_toString;
	this.getURI=Querystring_getURI;
	this.queryString=qs;
	
	if (this.queryString == null)
		this.queryString=location.search.substring(1,location.search.length)

	if (this.queryString.length == 0) return

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

		if (pair.length == 2)
			value = unescape(pair[1])
		else
			value = name
		
		this.params[name] = value
	}
}

function Querystring_get(key, default_) {
	// This silly looking line changes UNDEFINED to NULL
	if (default_ == null) default_ = null;
	
	var value=this.params[key]
	if (value==null) value=default_;
	
	return value
}

function Querystring_deleteQuery(key){
	for(var i in this.params){
		if(key==i) this.params[i]=null;
	}
}

function Querystring_toString(){
	var str="";
	for (var i in this.params) {
		var name = escape(i);
		var value= this.params[i];
		if(value!=null){
			value=escape(value);
			str=str+name+"="+value+"&";
		}
	}
	try{
		str=str.substring(0,str.length-1);
	}catch(e){}
	return str;
}
function Querystring_getURI(href){
	if(href==null){
		href=window.location.href;
	}
	var qlen=href.indexOf("?");
	if(qlen>=0){
		href=href.substring(0,qlen);
	}
	return href;
}