more nitpicking..
During the checkout procedure the breadcrumbs are inconsistent (and confusing on step 2) with the previous and subsequent pages.
I suggest
checkout_shipping.php
define('NAVBAR_TITLE_1', 'Checkout');
define('NAVBAR_TITLE_2', 'Shipping Method – Step 1');
checkout_payment.php
define('NAVBAR_TITLE_1', 'Checkout');
define('NAVBAR_TITLE_2', 'Payment Method - Step 2');
checkout_confirmation.php
define('NAVBAR_TITLE_1', 'Checkout');
define('NAVBAR_TITLE_2', 'Confirmation – Step 3');
Bookmarks