var uAgent  = navigator.userAgent.toUpperCase();
var aName  = navigator.appName.toUpperCase();
var uName = navigator.userAgent.toUpperCase();

//os
function checkOs(){
	if (uAgent.indexOf("MAC") >= 0) return "mac";
	if (uAgent.indexOf("WIN") >= 0) return "win";
	if (uAgent.indexOf("X11") >= 0) return "unix";
	return "";
}


//browser
function checkBrowser(){
	if (uName.indexOf("SAFARI") >= 0)  return "sf";
	if (uName.indexOf("OPERA") >= 0)  return "op";
	if (uName.indexOf("FIREFOX") >= 0)  return "ff";
	if (aName.indexOf("NETSCAPE") >= 0)  return "ns";
	if (aName.indexOf("MICROSOFT") >= 0) return "ie";
	return "";
}

//browser version
function checkBrowserVersion(){
	var browser = checkBrowser();
	var browserVersion = 0;
	var s = 0;
	var e = 0;
	var appVer  = navigator.appVersion;
	var uName  = navigator.userAgent.toUpperCase();

	if (browser == "sf"){
		s = uName.indexOf("SAFARI/",0);
		browserVersion = (uName.substring(s+7,s+99));
		if (browserVersion < 400) browserVersion = 1;
		if (browserVersion >= 400) browserVersion = 2;
	}if (browser == "op"){
		s = uName.indexOf("OPERA",0) + 6;
		e = uName.indexOf(" ",s);
		browserVersion = parseFloat(uName.substring(s,e));
	}if (browser == "ff"){
		s = uName.indexOf("FIREFOX/",0);
		browserVersion = parseFloat(uName.substring(s+8,s+8+3));
	}if (browser == "ns"){
		s = appVer.indexOf(" ",0);
		browserVersion = eval(appVer.substring(0,s));
		if (browserVersion >= 5) browserVersion++;
	}if (browser == "ie"){
		appVer  = navigator.userAgent;
		s = appVer.indexOf("MSIE ",0) + 5;
		e = appVer.indexOf(";",s);
		browserVersion = eval(appVer.substring(s,e));
	}
	return browserVersion;
}

os = checkOs();
browser = checkBrowser();
browserVersion = checkBrowserVersion();