$commentForm = new ZendX_JQuery_Form();
        $commentForm->setAttrib('action', 'DisplayQuiz/addComment');
        $commentForm->setAttrib('id', 'commentForm');
        $commentForm->setAttrib('class', 'flora');
        $commentForm->setMethod('post');

and then

        $tabForm->addSubForm($commentForm, 'commentForm');