My 404 Page

<?php ob_start()?>
<!DOCTYPE html>
<html>
<head>
<?php
header($_SERVER["SERVER_PROTOCOL"]." 404 Not Found");
?>
<meta http-equiv="Content-Type" content="text/html;charset=utf-8">
<meta name="robots" content="noindex, nocache">
<title>404 - ERROR</title>
</head>
<body>
<h2>Object not found!</h2>
<div>
The requested URL was not found on this server. If you entered the URL manually please check your spelling and try again.
<br/>
If you think this is a server error, please post in the bugs forum, <strong> Please include the last page you were on if its on our site AND THE URL YOU USED!!</strong><br/>
<img height="200" width="200" src="404.png" alt="404"/>
</div>
<br/>
<br/>
<br/>
<div>
Debug info:
<?php echo $_SERVER['HTTP_USER_AGENT'] ?>
</div>
</body>
</html>
<?php ob_flush()?>