public function categoriesAction()
 {
     $this->view->headScript()->appendFile(Zend_Registry::get('StaticBaseUrl') . 'application/modules/Book/externals/scripts/collapsible.js');
     $this->view->navigation = $navigation = Engine_Api::_()->getApi('menus', 'core')->getNavigation('book_admin_main', array(), 'book_admin_main_categories');
     $table = new Book_Model_DbTable_Categories();
     $this->view->categories = $table->getCategoriesByLevel(null, array('category_name'));
 }