public function ajaxValidAction()
 {
     $this->_helper->viewRenderer->setNoRender();
     $this->_helper->getHelper('layout')->disableLayout();
     $form = new Default_Form_Register();
     $form->isValidPartial($_POST);
     $msg = $form->getMessages();
     header('Content-type: application/json');
     echo Zend_Json::encode($msg);
 }