JS判断浏览器门类 _JavaScript

JS判断浏览器类型

<span?style="font-size:?medium;"><!DOCTYPE?html?PUBLIC?"-//W3C//DTD?XHTML?1.0?Transitional//EN"?"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">??
<html?xmlns="http://www.w3.org/1999/xhtml">??
<head>??
<meta?http-equiv="Content-Type"?content="text/html;?charset=utf-8"?/>??
<title>无标题文档</title>??
??
??<script?type="text/javascript">??
????????var?Sys?=?{};??
????????var?ua?=?navigator.userAgent.toLowerCase();??
????????if?(window.ActiveXObject)??
????????????Sys.ie?=?ua.match(/msie?([\d.]+)/)[1]??
????????else?if?(document.getBoxObjectFor)??
????????????Sys.firefox?=?ua.match(/firefox\/([\d.]+)/)[1]??
????????else?if?(window.MessageEvent?&&?!document.getBoxObjectFor)??
????????????Sys.chrome?=?ua.match(/chrome\/([\d.]+)/)[1]??
????????else?if?(window.opera)??
????????????Sys.opera?=?ua.match(/opera.([\d.]+)/)[1]??
????????else?if?(window.openDatabase)??
????????????Sys.safari?=?ua.match(/version\/([\d.]+)/)[1];??
??????????
????????//以下进行测试??
????????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>??
</head>??
??
<body>??
</body>??
</html>??
</span>??