public DataTable QuerySwitch(QueryType QT,
            ArrayList ParameterList
            )
        {
            DBO.OUT_PurchaseOrderDBO dbo = new OUT_PurchaseOrderDBO(ref USEDB);
            DataTable Dt;

            try
            {
                switch (QT)
                {
                    //case QueryType.ALL:
                    //    Dt = dbo.doQueryAll();
                    //    break;
                    //case QueryType.CODE:
                    //    Dt = dbo.doQueryByCode(ParameterList);
                    //    break;
                    case QueryType.ID:
                        Dt = dbo.GetMasterByPK(ParameterList);
                        break;
                    case QueryType.Custom:
                        Dt = dbo.GetMainByWhere1(ParameterList);
                        break;
                    default:
                        Dt = new DataTable();
                        break;
                }

                return Dt;
            }
            catch (Exception ex)
            {
                throw ex;
            }
        }