<script>
            //关于浏览器的信息
            var x = navigator;
            document.write("CodeName=" + x.appCodeName);
            document.write("<br />");
            document.write("MinorVersion=" + x.appMinorVersion);
            document.write("<br />");
            document.write("Name=" + x.appName);
            document.write("<br />");
            document.write("Version=" + x.appVersion);
            document.write("<br />");
            document.write("CookieEnabled=" + x.cookieEnabled);
            document.write("<br />");
            document.write("CPUClass=" + x.cpuClass);
            document.write("<br />");
            document.write("OnLine=" + x.onLine);
            document.write("<br />");
            document.write("Platform=" + x.platform);
            document.write("<br />");
            document.write("UA=" + x.userAgent);
            document.write("<br />");
            document.write("BrowserLanguage=" + x.browserLanguage);
            document.write("<br />");
            document.write("SystemLanguage=" + x.systemLanguage);
            document.write("<br />");
            document.write("UserLanguage=" + x.userLanguage);
        </script>

  <script>
            var nav = window.navigator.userAgent;
            //不知道你可以打开你的浏览器,把这句话写上,然后查看这句话里面出现的字符串,然后做判断就可以了
           document.write("代理："+nav); 
            var cb = "Unknown";
            if (nav.indexOf("Trident") != 1) { //IE
                cb = "IE";
            } else if (nav.indexOf("Firefox") != 1) { //火狐
                cb = "Firefox";
            } else if (nav.indexOf("Chrome") != 1) {  //谷歌
                cb = "Chrome";
            } 
            else if (nav.indexOf("Opera") != 1) { //欧朋
                cb = "Opera";
            }                    
           console.log(cb);

        </script>