private function createDeleteForm($id) {
        return $this->createFormBuilder()
                        ->setAction($this->generateUrl('admin_news_category_delete', array('id' => $id)))
                        ->setMethod('DELETE')
                        ->add('submit', 'submit', array('label' => 'Delete',
                            'attr' => array(
                                    'onclick' => 'return confirm("Estás seguro?")'
                            )))
                        ->getForm()
        ;
    }