if (navigator.appName == "Microsoft Internet Explorer" && parseInt(navigator.appVersion) >= 4) {
	var isIE4 = true
	var isNS4 = false
}
else if (navigator.appName == "Netscape" && parseInt(navigator.appVersion) >= 4) {
	var isIE4 = false
	var isNS4 = true
}
else {
	var isIE4 = false
	var isNS4 = false
}