Ads working on site but not on PHPbb

I get this error message:

Warning: main(./ad_network.php): failed to open stream: No such file or directory in /home/sanlucar/public_html/forum/includes/page_tail.php on line 42

Warning: main(./ad_network.php): failed to open stream: No such file or directory in /home/sanlucar/public_html/forum/includes/page_tail.php on line 42

Warning: main(): Failed opening './ad_network.php' for inclusion (include_path='.:/usr/lib/php:/usr/local/lib/php') in /home/sanlucar/public_html/forum/includes/page_tail.php on line 42

Code added to page_tail.php

include ($phpbb_root_path . 'ad_network.php');
$template->assign_vars(array('AD_NETWORK' => $ad_network[0]));
unset ($ad_network);
$template->pparse('overall_footer');

PHP:

Webiste is:
w w w.sanlucar-de-barrameda.com (removed as it's not quite ready yet...testing (forum is located at /forum)

What am I doing wrong here?

Ian

 

Ok I've got rid of the errors, but now the ads are not showing on the board!

I hard coded ad_network.php file

Changed this:
include ($phpbb_root_path . 'ad_network.php');

to:
include ($phpbb_root_path . '../ad_network.php');

And added this to the overallfooter.tpl

// -->
Powered by <a href="http://www.phpbb.com/" target="_phpbb" class="copyright">phpBB</a> {PHPBB_VERSION} © 2001, 2002 phpBB Group<br />{TRANSLATION_INFO}</span></div>
		</td>
	</tr>
</table>
<?php
	ini_set ("include_path", ini_get ("include_path") . ':../:../../:../../../:../../../../');
	include ('ad_network.php');
	echo $ad_network[0];
?>
</body>
</html>

Code (markup):

 

Doh......Now got it working, just read through all the instructions again.

Thanks.

Ian