帮忙看看这个有没有错误

<?
@ob_start();
@date_default_timezone_set('PRC');

$sender=$_POST['sender'];//sender共有11个字符串
$pass=substr($sender,'5');//截取sender后6位字符串
$ne=substr($sender,'-6');//截取sender前5位字符串
$name="新会员$ne";
$time=date('Y-m-d H:i:s');

include('data/config.php');//链接数据库
include('data/#data_class.php');//数据库类

$result=mysql_query("select * from `user_user` where `mobile`='$sender'");
$rows=mysql_fetch_array($result);
if($rows[mobile] == ''){}else{echo '该账户已存在!';
exit();
}//检测是否已存在该账号

$sql=mysql_query("insert into `user_user` (`mobile`,`name`,`pass`,`reg_time`) values ('$sender','$name','$pass','$time')");
if($sql){
echo '注册成功';
}else{
echo '注册失败';
exit();
}//插入账号密码等数据
?>