function Querystring(qs) 

{ 
	this.params = new Object()
	this.get=Querystring_get
	
	if (qs == null)
		qs=location.search.substring(1,location.search.length)

	if (qs.length == 0) return

	qs = qs.replace(/\+/g, ' ')
	var args = qs.split('&') 
	
	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_) 

{
	
	if (default_ == null) default_ = null;
	
	var value=this.params[key]
	if (value==null) value=default_;
	
	return value
}