public function cadastrarAction()
 {
     $form = new Application_Form_Categoria();
     $var = $this->getAllParams();
     if ($this->getRequest()->isPost()) {
         if ($form->isValid($var)) {
             $dados = $form->getValues();
             $inserir = array('categoria' => $dados['categoria']);
             $tb = new Application_Model_DbTable_Categoria();
             $tb->insert($inserir);
             $this->_helper->redirector->gotoSimpleAndExit('index');
         }
     }
     $this->view->form = $form;
 }