function detectBrowser()    {        var browser = navigator.appName        if(navigator.userAgent.indexOf("MSIE")>0){             var b_version = navigator.appVersion            var version = b_version.split(";");            var trim_Version = version[1].replace(/[ ]/g,"");            if ((browser=="Netscape"||browser=="Microsoft Internet Explorer"))            {                if(trim_Version == 'MSIE8.0' || trim_Version == 'MSIE7.0' || trim_Version == 'MSIE6.0'){                    alert('请使用IE9.0版本以上进行访问');                    return;                }            }        }   }    detectBrowser();