华谊金安:PHP登陆验证问题？解决+分

<?php
session_start();
$user_name=$_POST["user_name"];
$password=$_POST["password"];
session_register("user_name"); require_once("sys_conf.inc"); $link_id=mysql_connect($DBHOST,$DBUSER,$DBPWD); mysql_select_db($DBNAME);
$str="select user_name,password from user where user_name ='$user_name'";
$result=mysql_query($str,$link_id);
$rows=mysql_num_rows($result);
if($rows!=0)
{
list($name,$password)=mysql_fetch_row($result);
//如果密码输入正确
if (($user_name==$_POST["user_name"]) && ($password==$_POST["password"]))
{
$str="update user set online =1 where user_name ='$user_name' and password='$password'";
$result=mysql_query($str, $link_id);
require("display.php");
}
else
{
echo "<script LANGUAGE='javascript'>alert('用户名密码错误！');history.go(-1);</script>";
//require("login.php");
}
mysql_close($link_id);
?>

运行后Parse error: parse error in C:\AppServ\www\test\ch_user.php on line 33 但是第33行是最后的 ?>号啊。这是为什么？