Breadcrumb function for wp ecommerce and navxt to play together

WordPress:Breadcrumb function

function wordpress_breadcrumbs() {
 
  
  global $post;

  if(get_post_type($post) == 'wpsc-product'){
    return true;
  } else {
?>
  <div class="breadcrumbs">
    <?php 
    if(function_exists('bcn_display') && !is_front_page())
    {
        bcn_display();
    }

    ?>
</div>
<?php
}
}
add_action('thesis_hook_post_box_top', 'wordpress_breadcrumbs');