public function actionUpdate($id)
 {
     $discipline = DisciplineToTeacher::model()->findByPk($id);
     if ($discipline->id_teacher != Yii::app()->user->id) {
         throw new CHttpException(403, 'У вас недостаточно прав для выполнения указанного действия.');
     }
     if (isset($_POST['user'])) {
         $model = new DisciplineToUser();
         $valid = true;
         if (isset($_POST['addUser'])) {
             foreach ($_POST['user'] as $user) {
                 $model->id_user = $user;
                 $model->id_discipline = $id;
                 $valid = $model->save() && $valid;
                 $model->isNewRecord = true;
             }
         }
         if (isset($_POST['delUser'])) {
             foreach ($_POST['user'] as $user) {
                 $valid = $model->findByAttributes(array('id_user' => $user, 'id_discipline' => $id))->delete() && $valid;
             }
         }
         if ($valid) {
             $outUsers = $this->showStudent($discipline->id_group);
             $inUsers = $this->showStudentByDiscipline($discipline->id_group, $id);
             $outUsers = array_diff_key($outUsers, $inUsers);
             $this->renderPartial('_addStudents', array('inUsers' => $inUsers, 'outUsers' => $outUsers));
         }
         Yii::app()->end();
     }
     $outUsers = $this->showStudent($discipline->id_group);
     $inUsers = $this->showStudentByDiscipline($discipline->id_group, $id);
     $outUsers = array_diff_key($outUsers, $inUsers);
     if (isset($_POST['Discipline'])) {
         $discipline->attributes = $_POST['Discipline'];
         if ($discipline->save()) {
             $this->redirect(array('list'));
         }
     }
     $this->render('update', array('discipline' => $discipline, 'inUsers' => $inUsers, 'outUsers' => $outUsers));
 }