js获取浏览器类型

function add(){
            var userAgent = navigator.userAgent,
            rMsie = /(msie\s|trident.*rv:)([\w.]+)/,
            rFirefox = /(firefox)\/([\w.]+)/,
            rOpera = /(opera).+version\/([\w.]+)/,
            rChrome = /(chrome)\/([\w.]+)/,
            rSafari = /version\/([\w.]+).*(safari)/;
            var browser;
            var version;
            var ua = userAgent.toLowerCase();
            var stu_name;
            function uaMatch(ua) {
                var match = rMsie.exec(ua);
                if (match != null) {
                    alert("IE");
                    stu_name = $("#stu_name").text().split("\n");
                    alert(stu_name);
　　　　　　　　　　　　

var Sys = {};
var ua = navigator.userAgent.toLowerCase();
var s;
(s = ua.match(/msie ([\d.]+)/)) ? Sys.ie = s[1] :
(s = ua.match(/firefox\/([\d.]+)/)) ? Sys.firefox = s[1] :
(s = ua.match(/chrome\/([\d.]+)/)) ? Sys.chrome = s[1] :
(s = ua.match(/opera.([\d.]+)/)) ? Sys.opera = s[1] :
(s = ua.match(/version\/([\d.]+).*safari/)) ? Sys.safari = s[1] : 0;
if(Sys.ie == '8.0'){
alert("ie8");
}

                }
                var match = rFirefox.exec(ua);
                if (match != null) {
                    alert("rFirefox");
                    stu_name = $("#stu_name").val().split("\n");
                    alert(stu_name);
                }
                var match = rOpera.exec(ua);
                if (match != null) {
                    alert("rOpera");
                    stu_name = $("#stu_name").val().split("\n");
                    alert(stu_name);
                }
                var match = rChrome.exec(ua);
                if (match != null) {
                    alert("rChrome");
                    stu_name = $("#stu_name").val().split("\n");
                    alert(stu_name);
                }
                var match = rSafari.exec(ua);
                if (match != null) {
                    alert("rSafari");
                    stu_name = $("#stu_name").val().split("\n");
                    alert(stu_name);
                }
                if (match != null) {
                    alert("null");
                    stu_name = $("#stu_name").val().split("\n");
                    alert(stu_name);
                }
            }
            var browserMatch = uaMatch(userAgent.toLowerCase());
}