//public decimal CalculateCourierFee()
        //{
        //    using (FreeMarketEntities db = new FreeMarketEntities())
        //    {
        //        decimal totalWeight = GetTotalWeightOfOrder();
        //        if (totalWeight == 0)
        //            return 0;
        //        else
        //            return (decimal)db.CalculateDeliveryFee(totalWeight, Order.OrderNumber).FirstOrDefault();
        //    }
        //}

        public decimal CalculateCourierFeeAdhoc(int postalCode)
        {
            using (FreeMarketEntities db = new FreeMarketEntities())
            {
                decimal totalWeight = GetTotalWeightOfOrder();
                if (totalWeight == 0)
                {
                    return(0);
                }
                else
                {
                    return((decimal)db.CalculateDeliveryFeeAdhoc(totalWeight, postalCode).FirstOrDefault());
                }
            }
        }