public function actionFiltertt()
 {
     $course_id = isset($_POST['course_id']) ? $_POST['course_id'] : '';
     $listtest = WCourseLecture::listMyTestByCourse($course_id);
     $html = $this->renderPartial('/wCourseLecture/filter', array('data' => $listtest));
     echo $html;
     exit;
 }