public function deleteAction()
 {
     $authorization = Zend_Auth::getInstance();
     $identity = $authorization->getIdentity();
     if ($identity->user_type == "admin") {
         $id = $this->getRequest()->getParam('id');
         if ($id) {
             $model = new Application_Model_Materialtype();
             $model->deleteType($id);
         }
         $this->redirect('materialtype/add');
     } else {
         $this->redirect("materialtype/index");
     }
 }