public function refundTuition($id, $studentId, $classId, $refundTuition)
 {
     $instId = session('instId');
     try {
         $classModel = new \Home\Model\ClassModel();
         $studentModel = new \Home\Model\StudentModel();
         $institutionModel = new \Home\Model\InstitutionModel();
         //logModel
         $instBalanceChangeLogModel = new \Home\Model\InstBalanceChangeLogModel();
         $studentBalanceChangeLogModel = new \Home\Model\StudentBalanceChangeLogModel();
         $classModel->startTrans();
         //finance transaction part1 start
         $studentModel->addStudentBalance($refundTuition * 100, $studentId, $instId);
         $reason = 5;
         //学费返还给学生
         $studentBalanceChangeLogModel->savelog($studentId, $reason, $classId, $refundTuition * 100);
         $classModel->updateStudentTuitionById(-$refundTuition * 100, (int) $id, $instId);
         //finance transaction part1 end
         //finance transaction part2 start
         //change inst balance
         $institutionModel->updateInstitutionBalance(-$refundTuition * 100, $instId);
         $reason = 3;
         //退还学费给学生
         $instBalanceChangeLogModel->saveLog($instId, $reason, $studentId, -$refundTuition * 100);
         //finance transaction part2 end
         $data = "true";
         $classModel->commit();
     } catch (Exception $e) {
         $data = "false";
         $classModel->rollback();
     }
     $this->ajaxReturn($data);
 }