检测IE浏览器版本是否过低

<script type="text/javascript"> 
/*判断浏览器版本是否过低*/ 
$(document).ready(function() {s 
var b_name = navigator.appName; 
var b_version = navigator.appVersion; 
var version = b_version.split(";"); 
var trim_version = version[1].replace(/[ ]/g, ""); 
if (b_name == "Microsoft Internet Explorer") { 
/*如果是IE6或者IE7*/ 
if (trim_version == "MSIE7.0" || trim_version == "MSIE6.0") { 
alert("IE浏览器版本过低，请到指定网站去下载相关版本"); 
//然后跳到需要连接的下载网站 
//window.location.href="http://jiaoxueyun.com/download.jsp"; 
} 
} 
}); 
</script>