var name = navigator.appName;
var vers = navigator.appVersion;
vers = vers.substring(0,1); // or 0,4  could return 4.5 instead of just 4

if (name == "Microsoft Internet Explorer")  {

} else if (vers < 5) {

//url="netscape";
//url += vers + ".html";
window.location="http://www.cardblanks.com/netscape477_or_older.html";
}