判断浏览器类型

从无忧上抄的  记录一下

1

<script type="text/javascript">
alert(navigator.userAgent
.replace(/^.*(MSIE|Firefox|Chrome|Opera|Safari)[^0-9.]*([0-9.]*)[^0-9.]*.*$/i,"浏览器：$1 版本：$2")

.replace(/^(?!浏览器：).*$/g,"未知浏览器"))
</script>

2

<script> 
var Sys = (

function(s,t){return s("MSIE ")?(navigator.userAgent.substr(s("MSIE ")+4,1)):

(s("Firefox")?1:(s("Chrome")?2:(s("Opera")?3:0)));})(

function(s){return navigator.userAgent.indexOf(s)+1;});


alert(Sys)
</script> 

//5-9:IE5-IE9;
//1:firefox;
//2:chrome;
//3:opera;