Quick question, this is such a little problem but I need to get it working. I need PHP to send a browser to it's local 404 page, exactly the same way it would if a page didn't exist. Here's what I'm trying:

PHP Code:
<?php
header("HTTP/1.0 404 Not Found");
?> 
This page should send your browser to a 404 page located on your filesystem, however it isn't on the servers I'm using. A "location:" redirect works fine, however this doesn't. The most embarrasing part is that I pulled that code directly from the PHP site, and it still doesn't work.

I'm reading this but most of it is going over my head:
http://us4.php.net/header

What can I do with php to get the browser to show the local filesystem's 404 page?