private void machineTypeBox_SelectionChanged(object sender, SelectionChangedEventArgs e)
        {
            try
            {
                string    selectdMachine = machineTypeBox.SelectedValue.ToString();
                DataTable machinGrp      = DBManager.selectMachineGroups(selectdMachine);

                if (Convert.ToInt16(machinGrp.Rows[0][0].ToString()) == 4)
                {
                    operators = DBManager.selectOperators("5");
                }
                else
                {
                    operators = DBManager.selectOperators("9");
                }

                operatorNameBox.ItemsSource = operators.AsDataView();
            }
            catch
            {
            }
        }