// trap the errors
	function queryUrl(q) {
		if(q.length > 1) 
			this.q = q.substring(1, q.length);
		else 
			this.q = null;
		
		this.paramValue = new Array();
		if(q) {
			for(var i=0; i < this.q.split("&").length; i++) {
				this.paramValue[i] = this.q.split("&")[i];
			}
		}
		
		this.getparamValue = function() { return this.paramValue; }
		
		this.getValue = function(s) {
			for(var j=0; j < this.paramValue.length; j++) {
				if(this.paramValue[j].split("=")[0] == s)
					return this.paramValue[j].split("=")[1];
				}
			return false;
		}
		
		this.getParameters = function() {
			var a = new Array(this.getLength());
			for(var j=0; j < this.paramValue.length; j++) {
				a[j] = this.paramValue[j].split("=")[0];
			}
			return a;
		}
		
		this.getLength = function() { return this.paramValue.length; } 
	}

	function queryString(param)
	{
		var page = new queryUrl(window.location.search); 
		return unescape(page.getValue(param)); 
	}

	function trapError(param)
	{
		if (queryString(param) && (queryString(param)!= 'false') ){
			alert(queryString(param));
		}
	}