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>