获取浏览器版本信息

;(function(){
    var sys = {},
        ua = navigator.userAgent.toLowerCase(),
        s;
    (s=ua.match(/rv:([\d.]+)\) like gecko/))?sys={‘name‘:‘ie‘,‘ver‘:parseFloat(s[1])}:
    (s=ua.match(/msie ([\d.]+)/))?sys={‘name‘:‘ie‘,‘ver‘:parseFloat(s[1])}:
    (s=ua.match(/firefox\/([\d.]+)/))?sys={‘name‘:‘firefox‘,‘ver‘:parseFloat(s[1])}:
    (s=ua.match(/chrome\/([\d.]+)/))?sys={‘name‘:‘chrome‘,‘ver‘:parseFloat(s[1])}:
    (s=ua.match(/opera.([\d.]+)/))?sys={‘name‘:‘opera‘,‘ver‘:parseFloat(s[1])}:
    (s=ua.match(/version\/([\d.]+).*safari/))?sys={‘name‘:‘safari‘,‘ver‘:parseFloat(s[1])}:
    sys={‘name‘:‘unknow‘,‘ver‘:0};
    
    // 写入全局变量
    BROWSER_INFO = sys;
    ISIE6 = (!-[1,]&&!window.XMLHttpRequest);
    if(ISIE6){ alert("您的浏览器版本过低,为体验更好效果,请升级您的浏览器！"); }
})();