JavaScript判断浏览器类型及版本号

window["MzBrowser"] = {};
(function(){
    if (MzBrowser.platform) 
        return;
    var ua = window.navigator.userAgent;
    MzBrowser.platform = window.navigator.platform;
    
    MzBrowser.firefox = ua.indexOf("Firefox") > 0;
    MzBrowser.opera = typeof(window.opera) == "object";
    MzBrowser.ie = !MzBrowser.opera && ua.indexOf("MSIE") > 0;
    MzBrowser.mozilla = window.navigator.product == "Gecko";
    MzBrowser.netscape = window.navigator.vendor == "Netscape";
    MzBrowser.safari = ua.indexOf("Safari") > -1;
    
    if (MzBrowser.firefox) 
        var re = /Firefox(\s|\/)(\d+(\.\d+)?)/;
    else 
        if (MzBrowser.ie) 
            var re = /MSIE( )(\d+(\.\d+)?)/;
        else 
            if (MzBrowser.opera) 
                var re = /Opera(\s|\/)(\d+(\.\d+)?)/;
            else 
                if (MzBrowser.netscape) 
                    var re = /Netscape(\s|\/)(\d+(\.\d+)?)/;
                else 
                    if (MzBrowser.safari) 
                        var re = /Version(\/)(\d+(\.\d+)?)/;
                    else 
                        if (MzBrowser.mozilla) 
                            var re = /rv(\:)(\d+(\.\d+)?)/;
    
    if ("undefined" != typeof(re) && re.test(ua)) 
        MzBrowser.version = parseFloat(RegExp.$2);
})();

function aa(){
    if (MzBrowser.ie) {
        alert('您的浏览器是IE');
    }
    if (MzBrowser.firefox) {
        alert('您的浏览是Firefox');
    }
    alert(MzBrowser.version);
}

aa();