public int Xoa(int maloaihoatdong)
 {
     try
     {
         LinQDataContext db = new LinQDataContext(global::DAOAuction.Properties.Settings.Default.webdoantruongConnectionString);
       db.LOAIHOATDONG_delete(maloaihoatdong);
       db.SubmitChanges();
       return 0;
     }
     catch (Exception ex)
     {
         throw (ex);
     }
 }