var TRACKER_URL_3DV = "http://server2.3dvista.com/ServiceTracker/Tracker.ashx";

function insertTracker_3DV(userId)
{				  		
	var iframe = document.createElement("IFRAME");
   	iframe.id = "visitsFrame";
	iframe.style.display = "none";
	iframe.src = getTrackerURL_3DV(userId);			
    		
	document.body.appendChild(iframe);	  			  		
}

function getTrackerURL_3DV(userId)
{
	var url = TRACKER_URL_3DV;
	url = appendURLParameter_3DV(url, "user_id", userId.toString());
	url = appendURLParameter_3DV(url, "track_url", removeURLParameters_3DV(window.location.href));
	url = appendURLParameter_3DV(url, "referer_url", removeURLParameters_3DV(document.referrer));
	return url;
}

function appendURLParameter_3DV(url, name, value)
{
	return url + ((url.indexOf("?") < 0)? "?" : "&") + escape(name) + "=" + escape(value);
}

function removeURLParameters_3DV(url)
{
	var index = url.indexOf("?");
	if (index > 0)
		url = url.substr(0, index);
	return url;
}