// initialize the value of "browser"
var browser = "oldAndInTheWay";

// check for Netscape
if (navigator.appName == "Netscape") {
	browser = "ns" + parseInt(navigator.appVersion);
} else {
// check for MSIE
if (navigator.appName == "Microsoft Internet Explorer") {
	if (parseInt(navigator.appVersion) >= 4) {
		browser = "ie" + parseInt(navigator.appVersion);
       } else {
       	browser = "ie3";
		}
	}
}

if ((browser == "ns2") || (browser == "ns3") || (browser == "ie3") || (browser == "oldAndInTheWay")) {
// Include src code here
alert('We are sorry these pages require Netscape Navigator or Microsoft Explorer 4.x or higher')
window.close()
}