I have the following function with runs in response to an "onclick" event in a href string. tracker.php updates a database with "adID". It works perfectly In IE but does not work in Mozilla unless I put an alert message following the img.src statement. Can anybody help? function logAdID(adID) { if (img) { clearTimeout(timer); } img = new Image(); img.src = "http://www.diyadviser.com/Ads/tracker.php?adID=" + adID; return; }