public static function actionGetCourse()
 {
     $request = Yii::$app->request;
     $factID = $request->post('fact_id');
     $data = Course::getCourseName($factID);
     Yii::$app->response->format = 'json';
     //header json
     echo json_encode($data);
     /*print_r($data['coursename']);
       die();*/
 }