1.弹窗，让用户选择是否继续进行下一步

html>
body>
script type="text/JavaScript">
     var r=confirm("此系统仅支持chrom浏览器！IE、firefox不兼容！是否继续？");
     if (r==false)
     {
     window.history.back(-1);
     }
    script>
body>
html>

2.判断用户所用浏览器类型
 

html>
body>
script type="text/javascript">
        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) document.write('IE: ' + Sys.ie);
        if (Sys.firefox) document.write('Firefox: ' + Sys.firefox);
        if (Sys.chrome) document.write('Chrome: ' + Sys.chrome);
        if (Sys.opera) document.write('Opera: ' + Sys.opera);
        if (Sys.safari) document.write('Safari: ' + Sys.safari);
    script>
body>
html>