JS执行顺序关系到访问设备的判断

<script type="text/javascript">alert("这里先执行");</script>
<script type="text/javascript" src="jquery.min.js">alert("后执行");</script>

所以，有手机和PC站的话，就要将设备判断语句放到上面

<script type="text/javascript">

var sUserAgent = navigator.userAgent.toLowerCase();
var bIsIpad = sUserAgent.match(/ipad/i) == "ipad";
var bIsIphoneOs = sUserAgent.match(/iphone os/i) == "iphone os";
var bIsMidp = sUserAgent.match(/midp/i) == "midp";
var bIsUc7 = sUserAgent.match(/rv:1.2.3.4/i) == "rv:1.2.3.4";
var bIsUc = sUserAgent.match(/ucweb/i) == "ucweb";
var bIsAndroid = sUserAgent.match(/android/i) == "android";
var bIsCE = sUserAgent.match(/windows ce/i) == "windows ce";
var bIsWM = sUserAgent.match(/windows mobile/i) == "windows mobile";
if (!(bIsIphoneOs || bIsMidp || bIsUc7 || bIsUc || bIsAndroid || bIsCE || bIsWM)) {
window.location.href="PC.htm";//PC端页面
} else if (bIsIpad) {
window.location.href = "Pan.htm";//平板端页面
} else {
window.location.href = "MOB.htm";//手机端页面

}

</script>