thank you page needs to stay up longer

Is there any way to make the thank you page stay available for viewing longer ? the client needs to get the order number off of this page since a call center is using the cart not the customer

using authorize.net AIM

posted in wrong section, moved to the HOW to section

removed the re-direct to the page but still stays up for just a second but the cool thing is that it does go to the thank you page now

I tried slipping the order number in that code but get this error message on the page

Notice: Undefined variable: vars in /home/parts/public_html/rmgsilver/templates/gk_twn2/html/com_hikashop/checkout/after_end.php on line 13
Order number:

here is what i did

<?php
/**
* @package HikaShop for Joomla!
* @version 1.5.7
* @author hikashop.com
* @copyright (C) 2010-2012 HIKARI SOFTWARE. All rights reserved.
* @license GNU/GPLv3 www.gnu.org/licenses/gpl-3.0.html
*/
defined('_JEXEC') or die('Restricted access');
?>
<?php
$app =& JFactory::getApplication();
$app->enqueueMessage( JText::_('THANK_YOU_FOR_PURCHASE') );echo ' Order number: '.$vars;

as usual you guys rock

got it Nickolas thanks again