public function deleteDepartment()
 {
     $this->checkLogin();
     $id = $_GET['DP_id'];
     $Department = new DepartmentModel();
     $result = $Department->deleteDepartment($id);
     if ($result == true) {
         $this->success('添加成功', 'index');
     } else {
         $this->error("添加失败");
     }
 }