var ua = navigator.userAgent;
var brName = navigator.appName;
var brMajorVersion = parseInt(navigator.appVersion);

var IE3 = ua.indexOf("MSIE 3.0") != -1;

var IE4OrNewer = false;
var IE5 = false;
var IE55 = false;
var IE6 = false;
var NS4OrNewer = false;
var NS4 = false;
var Mozilla5OrNewer = false; // Netscape 6 is a version of Mozilla 5

if (brMajorVersion >= 4) {
	if (brName == "Microsoft Internet Explorer") {
		IE4OrNewer = true;
		IE5 = ua.indexOf("MSIE 5") != -1;
		IE55 = ua.indexOf("MSIE 5.5") != -1;
		IE6 = ua.indexOf("MSIE 6") != -1;
	} else if (brName == "Netscape" || brName == "Mozilla") { //I'm just guessing that non-Netscape versions of Mozilla will report their name as "Mozilla"
		NS4OrNewer = true;
		if (brMajorVersion == 4) {
			NS4 = true;
		}
		if (brMajorVersion >= 5) {
			Mozilla5OrNewer = true;
		}
	}
}