得到浏览器版本 MzBrowser对象
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);})();