I have an iframe embedded slideshow that's working well. The show rotates on the product page in place of the first image. I replaced code in tpl_modules_main_product_image.php as follows
Code:
<?php
/**
 * Module Template
 *
 * @package templateSystem
 * @copyright Copyright 2003-2005 Zen Cart Development Team
 * @copyright Portions Copyright 2003 osCommerce
 * @license http://www.zen-cart.com/license/2_0.txt GNU Public License V2.0
 * @version $Id: tpl_modules_main_product_image.php 3208 2006-03-19 16:48:57Z birdbrain $
 */

?>

<iframe scrolling="no" marginheight="0" marginwidth="0" width="338" height="338" frameborder="0" src="images/<?php echo $products_name ?>/album_slide.php"
></iframe>
</div>
This works when there's a directory in the images directory with certain files and images for the product. When the directory isn't there, the iframe doesn't work. What I'd like to know is how to place the contents of the iframe tag into the original tpl_modules_main_product_image.php with an IF statement to look for the directory with the name of the product. If the directory isn't there yet, go ahead and load the regular contents. This way, if the directory isn't set up for any given product yet, it will default to the regular product page.

I hope I'm being clear enough. here's another way to put it:
IF products_name directory exists then <iframe stuff>
ELSE regular contents of tpl_prod_img