private void RefreshFields(ProductOrderDetail tmp)
 {
     _UnitPrice = tmp.UnitPrice;
     _Quantity  = tmp.Quantity;
     _Discount  = tmp.Discount;
     _OrderDetailInfoExtension.Refresh(this);
     _MyOrder   = null;
     _MyProduct = null;
     OnChange();            // raise an event
 }
        public static void Refresh(Product myProduct, ProductOrderDetail tmp)
        {
            OrderDetailInfo tmpInfo = GetExistingByPrimaryKey(tmp.OrderID, myProduct.ProductID);

            if (tmpInfo == null)
            {
                return;
            }
            tmpInfo.RefreshFields(tmp);
        }