Pure CSS Mega Menu

[Design75]

My Original tpl header:

" </div>

<?php } // no HEADER_SALES_TEXT or SHOW_BANNERS_GROUP_SET2 ?>


</div>

<br class="clearBoth" />
<!--eof-branding display-->



<!--bof-navigation display-->
<div id="navMainWrapper">
<div id="navMain">
<ul class="back">
<li><?php echo '<a href="' . HTTP_SERVER . DIR_WS_CATALOG . '">'; ?><?php echo HEADER_TITLE_CATALOG; ?></a> | </li>
<?php if ($_SESSION['customer_id']) { ?>
<li><a href="<?php echo zen_href_link(FILENAME_LOGOFF, '', 'SSL'); ?>"><?php echo HEADER_TITLE_LOGOFF; ?></a> | </li>
<li><a href="<?php echo zen_href_link(FILENAME_ACCOUNT, '', 'SSL'); ?>"><?php echo HEADER_TITLE_MY_ACCOUNT; ?></a> | </li>
<?php
} else {
if (STORE_STATUS == '0') {
?>
<li><a href="<?php echo zen_href_link(FILENAME_LOGIN, '', 'SSL'); ?>"><?php echo HEADER_TITLE_LOGIN; ?></a> | </li>
<?php } } ?>
<li><img src="<?php echo $template->get_template_dir('',DIR_WS_TEMPLATE, $current_page_base,'images').'/'.HEADER_ICON_CART ?>" alt="cart icon" class="cart-icon" /><a href="<?php echo zen_href_link(FILENAME_SHOPPING_CART, '', 'NONSSL'); ?>"><?php echo $_SESSION['cart']->count_contents();?> <?php echo HEADER_TITLE_CART_ITEMS; ?> - <?php echo $currencies->format($_SESSION['cart']->show_total());?></a> | </li>
<li><a href="<?php echo zen_href_link(FILENAME_CHECKOUT_SHIPPING, '', 'SSL'); ?>"><?php echo HEADER_TITLE_CHECKOUT; ?></a></li>
<?php if ($_SESSION['cart']->count_contents() != 0) { ?>
<?php }?>
</ul>
</div>
<br class="clearBoth" />
</div>
<!--eof-navigation display-->





<!--eof-header logo and navigation display-->


<!--bof-optional categories tabs navigation display-->
<?php require($template->get_template_dir('tpl_modules_categories_tabs.php',DIR_WS_TEMPLATE, $current_page_base,'templates'). '/tpl_modules_categories_tabs.php'); ?>
<!--eof-optional categories tabs navigation display-->

<!--bof handheld menu display-->
<?php require($template->get_template_dir('tpl_modules_mobile_categories_tabs.php',DIR_WS_TEMPLATE, $current_page_base,'templates'). '/tpl_modules_mobile_categories_tabs.php'); ?>
<!--eof handheld menu display-->

<!--bof-header ezpage links-->
<?php if (EZPAGES_STATUS_HEADER == '1' or (EZPAGES_STATUS_HEADER == '2' and (strstr(EXCLUDE_ADMIN_IP_FOR_MAINTENANCE, $_SERVER['REMOTE_ADDR'])))) { ?>
<?php require($template->get_template_dir('tpl_ezpages_bar_header.php',DIR_WS_TEMPLATE, $current_page_base,'templates'). '/tpl_ezpages_bar_header.php'); ?>
<?php } ?>
<!--eof-header ezpage links-->
</div>
<?php } ?>"



-After the code is added (I am adding it in the correct place, right?):



</div>

<?php } // no HEADER_SALES_TEXT or SHOW_BANNERS_GROUP_SET2 ?>


</div>

<br class="clearBoth" />
<!--eof-branding display-->



<!--bof-navigation display-->
<div id="navMainWrapper">
<div id="navMain">
<ul class="back">
<li><?php echo '<a href="' . HTTP_SERVER . DIR_WS_CATALOG . '">'; ?><?php echo HEADER_TITLE_CATALOG; ?></a> | </li>
<?php if ($_SESSION['customer_id']) { ?>
<li><a href="<?php echo zen_href_link(FILENAME_LOGOFF, '', 'SSL'); ?>"><?php echo HEADER_TITLE_LOGOFF; ?></a> | </li>
<li><a href="<?php echo zen_href_link(FILENAME_ACCOUNT, '', 'SSL'); ?>"><?php echo HEADER_TITLE_MY_ACCOUNT; ?></a> | </li>
<?php
} else {
if (STORE_STATUS == '0') {
?>
<li><a href="<?php echo zen_href_link(FILENAME_LOGIN, '', 'SSL'); ?>"><?php echo HEADER_TITLE_LOGIN; ?></a> | </li>
<?php } } ?>
<li><img src="<?php echo $template->get_template_dir('',DIR_WS_TEMPLATE, $current_page_base,'images').'/'.HEADER_ICON_CART ?>" alt="cart icon" class="cart-icon" /><a href="<?php echo zen_href_link(FILENAME_SHOPPING_CART, '', 'NONSSL'); ?>"><?php echo $_SESSION['cart']->count_contents();?> <?php echo HEADER_TITLE_CART_ITEMS; ?> - <?php echo $currencies->format($_SESSION['cart']->show_total());?></a> | </li>
<li><a href="<?php echo zen_href_link(FILENAME_CHECKOUT_SHIPPING, '', 'SSL'); ?>"><?php echo HEADER_TITLE_CHECKOUT; ?></a></li>
<?php if ($_SESSION['cart']->count_contents() != 0) { ?>
<?php }?>
</ul>
</div>
<br class="clearBoth" />
</div>
<!--eof-navigation display-->





<!--eof-header logo and navigation display-->


<!--bof-optional categories tabs navigation display-->
<?php require($template->get_template_dir('tpl_modules_categories_tabs.php',DIR_WS_TEMPLATE, $current_page_base,'templates'). '/tpl_modules_categories_tabs.php'); ?>
<!--eof-optional categories tabs navigation display-->

<!--bof handheld menu display-->
<?php require($template->get_template_dir('tpl_modules_mobile_categories_tabs.php',DIR_WS_TEMPLATE, $current_page_base,'templates'). '/tpl_modules_mobile_categories_tabs.php'); ?>
<!--eof handheld menu display-->

<!--bof-header ezpage links-->
<?php if (EZPAGES_STATUS_HEADER == '1' or (EZPAGES_STATUS_HEADER == '2' and (strstr(EXCLUDE_ADMIN_IP_FOR_MAINTENANCE, $_SERVER['REMOTE_ADDR'])))) { ?>
<?php require($template->get_template_dir('tpl_ezpages_bar_header.php',DIR_WS_TEMPLATE, $current_page_base,'templates'). '/tpl_ezpages_bar_header.php'); ?>
<?php } ?>
<!--eof-header ezpage links-->
</div>
<!--bof-mega menu display-->
<?php require($template->get_template_dir('tpl_mega_menu.php',DIR_WS_TEMPLATE, $current_page_base,'common'). '/tpl_mega_menu.php');?>
<!--eof-mega menu display-->
<div class="clearBoth"></div>
<?php } ?>

A white page or partial white page usially means there is a errorlog file created. go to your log folder in the zen cart installation and see if there are any. You can post the contents of the latest one here, and we can help you better.