I make this small function, hope it helps. Here you can find the latest version browserDetection
function detectBrowser(userAgent){
var chrome = /.*(Chrome\/).*(Safari\/).*/g;
var firefox = /.*(Firefox\/).*/g;
var safari = /.*(Version\/).*(Safari\/).*/g;
var opera = /.*(Chrome\/).*(Safari\/).*(OPR\/).*/g
if(opera.exec(userAgent))
return "Opera"
if(chrome.exec(userAgent))
return "Chrome"
if(safari.exec(userAgent))
return "Safari"
if(firefox.exec(userAgent))
return "Firefox"
}