//Check for old IE versions
if(navigator.appName == "Microsoft Internet Explorer" && parseFloat(navigator.appVersion.substring(22,25)) <= 5.0)
	window.location.href = "/update.php";
//Check for old Netscape versions 
else if(navigator.appName == "Netscape" && parseFloat(navigator.appVersion.substring(0,3)) < 5.0)
	window.location.href = "/update.php";