browser_version= parseInt(navigator.appVersion);
browser_type = navigator.appName;

if (browser_type == "Microsoft Internet Explorer" && (browser_version >= 4)) {
document.write("<input type=text size=12 name=terms class=field>");
document.write("<input type=submit name=Submit value=Search class=button>");
} 
else if (browser_type == "Netscape" && (browser_version >= 4)) {
document.write("<input type=text name=terms size=5>");
document.write("<input type=submit name=Submit value=Search>");
}