浏览器内核

说实在得，我现在发现通过userAgent判断内核，貌似也不太好使。

function getBrowser() {    
    var ua = window.navigator.userAgent;    
    var isIE = window.ActiveXObject != undefined && ua.indexOf("MSIE") != -1;    
    var isFirefox = ua.indexOf("Firefox") != -1;    
    var isOpera = window.opr != undefined;    
    var isChrome = ua.indexOf("Chrome") && window.chrome;    
    var isSafari = ua.indexOf("Safari") != -1 && ua.indexOf("Version") != -1;    
    if (isIE) {    
        return "IE";    
    } else if (isFirefox) {    
        return "Firefox";    
    } else if (isOpera) {    
        return "Opera";    
    } else if (isChrome) {    
        return "Chrome";    
    } else if (isSafari) {    
        return "Safari";    
    } else {    
        return "Unkown";    
    }    
}