public function actionAddLivro()
 {
     $model = new Livro();
     // uncomment the following code to enable ajax-based validation
     /*
     if(isset($_POST['ajax']) && $_POST['ajax']==='livro-_form_livro-form')
     {
         echo CActiveForm::validate($model);
         Yii::app()->end();
     }
     */
     if (isset($_POST['Livro'])) {
         $model->attributes = $_POST['Livro'];
         if ($model->validate()) {
             // form inputs are valid, do something here
             return;
         }
     }
     $this->render('_form_livro', array('model' => $model));
 }