/**
 * Client-side access to querystring name=value pairs.
 * 
 * 
 * @usage:
 * var qs = new Querystring();
 * qs.get(name[, default_value])
 * 
 */
function QueryString(qs) { // optionally pass a querystring to parse
	this.params = new Object()
	this.get=QueryString_get

	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 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
}