大家看一下这个程序有什么错误

<?php

/**************************

@Filename: filename.php

@Version : 0.0.1

@Author  : leo

@Update  : 2007-11-01

@Content : PHP by Editplus

**************************/

session_cache_expire(30);

session_start();

if(isset($_SESSION['user']))

{

	header("Location:money.html");

	exit;

}

require('dbconnect.php');

$nickname=$_POST['name'];

$password=$_POST['password'];

$password=md5($password);



$sql="select * from user_login where name='$nickname' and password='password'";

$re=mysql_query($sql,$con);

$result=mysql_fetch_array($re);

if(!empty($result))

{

session_register("user");

$user=$nickname;

header("Location:money.html");

}

else

{

  die("登录失败".mysql_error());

}

?>

editplus编译显示
E:\WEB\www\mine\checklogin.php(line 22): Global variable 'con' is used without being assigned. You are probably relying on register_globals feature of PHP. Note that this feature is off by default.