Drupal分层菜单主题

I've created a hierarchical main menu with drupal 7, looks like this: http://dl.dropbox.com/u/16019885/Unbenannt.PNG

Now, i'm trying to fetch this menu via the following php code within my page.tpl.php:

<?php print theme('links__system_main_menu', array(
    'links' => $main_menu, 
    'attributes' => array(
        'id' => 'menu'
    )
)); ?>

And i've added this function to my template.php http://drupal.org/node/855698#comment-4478948

But I still get just a normal menu.

Here is, what it looks like: http://pastebin.com/ApukJY0w

You need to setup the parent menu items as "Show as expanded".

To achieve this, in admin/structure/menu/manage/main-menu/list, edit the parent menu item and check "Show as expanded".