Help with Previous Page Code

[kamelion0927]

I'm trying to alter product_info_display.php so that if the customer gets to that page from featured products, instead of seeing the prev and next buttons, they see a "back to featured products" button but am having trouble with the correct variable to use.

I thought the easiest way to implement this change would be to use the zen_back_link() function so I've tried several variations such as

<!--bof Top Navigation-->
<?php if ($link == 'featured_products') { ?>
<div class="backtoFeatured"><?php echo '<a href="' . zen_href_link(FILENAME_FEATURED_PRODUCTS) . '">' . zen_image_button(BUTTON_IMAGE_BACK, BUTTON_BACK_ALT) . '</a>'; ?></div>
<?php } else { ?>
<!--bof Prev/Next top position -->
<?php if (PRODUCT_INFO_PREVIOUS_NEXT == 1 or PRODUCT_INFO_PREVIOUS_NEXT == 3) { ?>
<?php
/**
 * display the product previous/next helper
 */
require($template->get_template_dir('/tpl_products_next_previous.php',DIR_WS_TEMPLATE, $current_page_base,'templates'). '/tpl_products_next_previous.php'); ?>
<?php } ?>
<!--eof Prev/Next top position-->
<?php } ?>
<!--eof Top Navigation-->

and

<!--bof Top Navigation-->
<?php if (zen_back_link() == 'featured_products') { ?>
<div class="backtoFeatured back"><?php echo '<a href="' . zen_href_link(FILENAME_FEATURED_PRODUCTS) . '">' . zen_image_button(BUTTON_IMAGE_BACK, BUTTON_BACK_ALT) . '</a>'; ?></div>
<?php } else { ?>
<!--bof Prev/Next top position -->
<?php if (PRODUCT_INFO_PREVIOUS_NEXT == 1 or PRODUCT_INFO_PREVIOUS_NEXT == 3) { ?>
<?php
/**
 * display the product previous/next helper
 */
require($template->get_template_dir('/tpl_products_next_previous.php',DIR_WS_TEMPLATE, $current_page_base,'templates'). '/tpl_products_next_previous.php'); ?>
<?php } ?>
<!--eof Prev/Next top position-->
<?php } ?>
<!--eof Top Navigation-->

but I'm obviously oblivious as to what the correct variable is. Any assistance would be greatly appreciated.