简单的jquery用户名唯一性验证

<?php $name=$_GET['name']; mysql_connect("localhost","root","111"); mysql_select_db("book"); $sql="select * from `admins` where `name`='".$name."'"; $que=mysql_query($sql); $num=mysql_num_rows($que); if($num==0){ echo "用户名可以使用"; }else{ echo "用户名已被注册"; } ?>