var browser = "";
var browsername = navigator.appName;
var browserversion = parseInt(navigator.appVersion);

if (browsername == "Netscape") {
	browser = "ns" + browserversion;
	} else {
	if (browsername == "Microsoft Internet Explorer") {
		if (browserversion >= 4) {
			browser = "ie" + browserversion;
		} else {
			browser = "ie3";
		}
	}
}

function popNav(url,name,features) {
   if ((browser == "ns3","ns4") || (browser == "ie4")) {
   popBox = window.open(url,name,features);
   popBox.focus();
	 } else {
		  if (browser == "ie3") {
		  popBox = window.open(url,name,features);
		  }  
   }
}