/**
  * Updates an existing Grades model.
  * If update is successful, the browser will be redirected to the 'view' page.
  * @param integer $id
  * @return mixed
  */
 public function actionUpdate()
 {
     $username = Yii::$app->user->identity->username;
     $users = User::find()->all();
     $grades = Grades::find()->all();
     $model = new Grades();
     $tuitions = Tuitionfees::find()->all();
     foreach ($users as $user) {
         foreach ($tuitions as $tuition) {
             if ($user->username == $username && $user->id == $tuition->tuitionfee_id) {
                 $id = $tuition->tuitionfee_id;
                 $model = $this->findModel($id);
                 if ($model->load(Yii::$app->request->post()) && $model->save()) {
                     $fileName = $model->tuitionfee_id . "regform";
                     $model->file = UploadedFile::getInstance($model, 'file');
                     if ($model->file != null) {
                         $model->file->saveAs('uploads/' . $fileName . '.' . $model->file->extension);
                         $model->tuitionfee_registrationForm = 'uploads/' . $fileName . '.' . $model->file->extension;
                     }
                     $model->save();
                     return $this->redirect(['view', 'id' => $model->tuitionfee_id]);
                     return $this->redirect(['view', 'id' => $model->tuitionfee_id]);
                 } else {
                     return $this->render('update', ['model' => $model]);
                 }
             }
         }
     }
 }