public virtual List <doTbt_BillingBasic> GetBillingBasic(string contractCode, string billingOCC, string billingTargetCode, string billingClientCode, string billingOfficeCode, string c_CURRENCY_LOCAL, string c_CURRENCY_US)
        {
            BLDataEntities context = new BLDataEntities();

            return(context.GetBillingBasic(contractCode, billingOCC, billingTargetCode, billingClientCode, billingOfficeCode, c_CURRENCY_LOCAL, c_CURRENCY_US).ToList());
        }