PHP error after editing conditions.php

[noname27]

Hello,
basically, i installed a template for osCommerce and all was going well everything worked perfectly...then, today, i went to insert the shipping/privacy and conditions text which i had a few problems with but managed to sort them out. Then...i wanted to rename the "Conditions of Use" to "About Us" and changed all the conditions.php files to about_us.php then since it was not working i changed everything back to how it was (i think) and now when you go into the Conditions of Use link this message comes up :
Internal Server Error

The server encountered an internal error or misconfiguration and was unable to complete your request. Please contact the server administrator, webmaster@cougar-raceparts.com and inform them of the time the error occurred, and anything you might have done that may have caused the error.
More information about this error may be available in the server error log.

Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.

I looked in the errorlog and copied this:

[13-Mar-2008 13:28:22] PHP Fatal error: require() [<a href='function.require'>function.require</a>]: Failed opening required 'includes/languages/english/FILENAME_ABOUT_US' (include_path='.:/usr/local/php52/pear') in /home/cougarra/public_html/shop/conditions.php on line 12

but i have already renamed all the "about_us.php" back to "conditions.php"

Also, in conditions.php I have pasted the code here.
it's not a lot so here's all of it.
line 12 from the top is the one in red! (i think)


<?php
/*
$Id: conditions.php,v 1.4 2002/11/19 01:48:08 dgw_ Exp $

Copyright (c) 2008 CougarPowerMotorsport
Released under the GNU General Public License
*/
define('NAVBAR_TITLE', 'Conditions');
define('HEADING_TITLE', 'Conditions');
define('TEXT_INFORMATION', 'Put here your conditions of use information.');
?>


Please help...if you can!!!

Thanks,

George