var isNS3, isNS4, isNS6, isNS4above, isIE, isIE4, isIE5, isOpera3, isOpera4, isFirefox, isSafari, isMozilla, isNetscape;
var isWin, isWinNT, isWin98, isWin95, isWin2000, isMac, isLinux, isUnix;
var isBrand = navigator.appName;
var agt = navigator.userAgent.toLowerCase();
var appVer = navigator.appVersion.toLowerCase();
var navVer = parseInt(navigator.appVersion);
var os = "unknown";

isOpera = (agt.indexOf("opera") != -1) ? true : false
isOpera3 = (agt.indexOf("opera 3") != -1) ? true : false
isOpera4 = (agt.indexOf("opera 4") != -1) ? true : false
if(isBrand == "Netscape")
{
	isFirefox = (agt.indexOf("firefox") != -1) ? true : false
	isSafari= (agt.indexOf("safari") != -1) ? true : false
	isMozilla= (agt.indexOf("gecko") != -1) ? true : false
	isNS3 = (navVer < 4 && !isOpera) ? true : false
	isNetscape = (agt.indexOf("netscape") != -1) ? true : false
	if(!isOpera)
	{
		isNS4 = (navVer < 5 && navVer > 3) ? true : false
		isNS4above = (navVer >= 4) ? true : false
		isNS6 = (navVer >= 5) ? true : false
	}
}
if(isOpera && navVer > 6)
{
	isNS6=true;
	isOpera=false;
}
isIE = (agt.indexOf("msie") != -1) ? true : false
isIE4 = (agt.indexOf("msie 4") != -1) ? true : false
isIE5 = (agt.indexOf("msie 5") != -1) ? true : false

isWin = (agt.indexOf('windows') != -1) ? true : false;
isWin2000 = (agt.indexOf('windows nt 5') != -1) ? true : false;
isWinNT = ((agt.indexOf('winnt') != -1 || agt.indexOf('windows nt') != -1) && !isWin2000) ? true : false;
isWin98 = (agt.indexOf('win98') != -1 || agt.indexOf('windows 98') != -1) ? true : false;
isWin95 = (agt.indexOf('win95') != -1 || agt.indexOf('windows 95') != -1) ? true : false;
isMac = (agt.indexOf('mac') != -1 || agt.indexOf('macintosh') != -1) ? true : false;
isLinux = (agt.indexOf('linux') != -1) ? true : false;
isUnix = (agt.indexOf('unix') != -1) ? true : false;