var sUserAgent = navigator.userAgent; //浏览器判断值  

            //检测Opera、KHTML  
            var isOpera = sUserAgent.indexOf("Opera") > -1;
            var isKHTML = sUserAgent.indexOf("KHTML") > -1 || sUserAgent.indexOf("Konqueror") > -1 || sUserAgent.indexOf("AppleWebKit") > -1;
            //检测IE、Mozilla  
            var isIE = sUserAgent.indexOf("compatible") > -1 && sUserAgent.indexOf("MSIE") > -1 && !isOpera;
            var isMoz = sUserAgent.indexOf("Gecko") > -1 && !isKHTML;

            //检测操作系统  

            //navigator.platform  运行浏览器的计算机平台的字符串表示  

            var isWin = (navigator.platform == "Win32") || (navigator.platform == "Windows");
            var isMac = (navigator.platform == "Mac68K") || (navigator.platform == "MacPPC") || (navigator.platform == "Macintosh");
            var isUnix = (navigator.platform == "X11") && !isWin && !isMac;
            if (isOpera) document.write("Opera ");
            if (isKHTML) document.write("KHTML ");
            if (isIE) document.write("IE ");
            if (isMoz) document.write("Mozilla ");
            if (isWin) document.write("Windows");
            if (isMac) document.write("Mac");
            if (isUnix) document.write("Unix");