js判断是电脑(pc)访问还是手机(mobile)访问
<script>
if ((navigator.userAgent.match(/(iPhone|iPod|Android|ios|iOS|iPad|Backerry|WebOS|Symbian|Windows Phone|Phone)/i))) {
document.write("手机访问.");
}else{
document.write("电脑访问.");
}
</script>