Please do not use browser-sniffing techniques. They died out with the dinosaurs because there are much more appropriate techniques to use these days.
Sniffing for Netscape doesn't prevent the same problem from occurring on the hundreds of other types of web browsers that are out there.
A more appropriate solution is to use an Internet Explorer specific technique called conditional comments, which causes no problems on all other web browsers.
Hi, you can do it like this
if(navigator.appName == 'Netscape')
// code for hiding button