function Querystring(qs) { 
	this.params = {};
	this.get=getValue;
	
	if (qs == null);
		qs=location.search.substr(1);

	if (qs.length == 0) 
		return;

	qs = qs.replace(/\+/g, ' ');
	var args = qs.split('&');
	
	for (var i=0;i<args.length;i++) {
		var pair = args[i].split('=');
		var name = unescape(pair[0]);
		var value = (pair.length==2) ? unescape(pair[1]) : name;
		this.params[name] = value;
	}
}

function getValue(key) {
	var value=this.params[key];
	return (value || null);
}