var userAgent = navigator.userAgent.toLowerCase();

KrifaBrowserUtil = {
    version: (userAgent.match(/.+(?:rv|it|ra|ie|me)[\/: ]([\d.]+)/) || [])[1],
    isChrome: /chrome/.test(userAgent),
    isSafari: /webkit/.test(userAgent) && !/chrome/.test(userAgent),
    isOpera: /opera/.test(userAgent),
    isIE: /msie/.test(userAgent) && !/opera/.test(userAgent),
    isFirefox: /mozilla/.test(userAgent) && !/(compatible|webkit)/.test(userAgent)
};