function startTrack(uid) {
        var myref = escape(document.referrer);
        if (myref == "") {
                myref = 'direct';
        }
        sendData(uid,myref);
}

function sendData(img,ref) {
        var link = "http://tracking.empreso.com/images/"+ img + "_" + ref + ".png";
        document.write("<img src='" + link + "' />");
}