} // Execute_Insert(string st)

        public bool Valid_SalesMan(string un, string pas)
        {
            bool             ret = false;
            OracleDataReader odr;

            odr = Execute_Query(MyQueryBuilder.Select_Salesman_Pass(un, pas));
            if (odr.Read() && odr.GetOracleValue(0).ToString().Equals(un))
            {
                ret = true;
            }
            return(ret);
        } // Valid_SalesMan(string un, string pas)
        } // SalesMan_Exist(string un)

        public bool Add_SalesMan(string un, string pas)
        {
            OracleDataReader odr;
            bool             ret = false;

            try
            {
                if (!SalesMan_Exist(un))
                {
                    Add_SalesMan_Force(un, pas);
                }
                odr = Execute_Query("" + MyQueryBuilder.Select_Salesman_Pass(un, pas));
                if (odr.Read() && odr.GetOracleValue(0).ToString().Equals(un))
                {
                    ret = true;
                }
            }
            catch (OracleException ex)
            {
                return(ret);
            }
            return(ret);
        } // Add_SalesMan(string un, string pas)