判断浏览器

<script >
    var userAgent = navigator.userAgent; 
    var isOpera = userAgent.indexOf("Opera") > -1; 
    var isMaxthon = userAgent.indexOf("Maxthon") > -1 ; 
    var isIE = userAgent.indexOf("compatible") > -1 && userAgent.indexOf("MSIE") > -1 && !isOpera ; 
    var isFF = userAgent.indexOf("Firefox") > -1 ; 
    var isSafari = userAgent.indexOf("Safari") > -1 && userAgent.indexOf("Chrome") < 1 ; 
    var isChrome = userAgent.indexOf("Chrome") > -1 ;
    var isIE5 = isIE55 = isIE6 = isIE7 = isIE8 = false;
     
    if(isFF){document.write("当前浏览器是  Firefox");}
    if(isMaxthon){document.write("当前浏览器是 傲游(webkit核心)");}
    if(isOpera){document.write("当前浏览器是  Opera");}
    if(isSafari){document.write("当前浏览器是  Safari");}
    if(isChrome){document.write("当前浏览器是  Chrome");}
    if(isIE){document.write("当前浏览器是  IE");}
</script>