js判断浏览器版本(IE,FF,Chrome,Opear,Safari)(转)

1. 五大浏览器判断

<script type="text/javascript">
var Sys = {};
var ua = navigator.userAgent.toLowerCase();
var s;
(s = ua.match(/msie ([\d.]+)/))? Sys.ie = s[1]:
(s = ua.match(/firefox\/([\d.]+)/))? Sys.firefox= s[1]:
(s = ua.match(/chrome\/([\d.]+)/))? Sys.chrome= s[1]:
(s = ua.match(/opera.([\d.]+)/))? Sys.opera= s[1]:
(s = ua.match(/version\/([\d.]+).*safari/))? Sys.safari= s[1]: 0;

//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>

2.IE浏览器版本

<!--[if IE]>
<script type="text/javascript">
alert("ie")
</script>
<![endif]-->
<!--[if IE 6]>
<script type="text/javascript">
alert("ie6")
</script>
<![endif]-->
<!--[if IE 7]>
<script type="text/javascript">
alert("ie7")
</script>
<![endif]-->