var agt=navigator.userAgent.toLowerCase();
var is_ie =((agt.indexOf("msie 5.5\; windows nt 5.0")!= -1) || (agt.indexOf("msie 5.01\; windows nt 5.0")!= -1));  
function win2000() {
if (is_ie == true) {
window.open('/security.php3','newin','toolbar=yes,location=top,directories=0,status=0,resizable=yes,menubar=yes,scrollbars=yes,width=350,height=200');
	}
}