private void editVehicle()
        {
            ClsVehicle lcVehicle = (ClsVehicle)lstLicencePlates.SelectedItem;

            if (lcVehicle != null && lcVehicle.ViewEdit())
            {
                updateDisplay();
            }
        }
        private void btnAddVehicle_Click(object sender, EventArgs e)
        {
            ClsVehicle lcVehicle = new ClsVehicle();

            if (lcVehicle != null && lcVehicle.ViewEdit())
            {
                ClsVehicleBusiness.VehicleList.Add(lcVehicle.RegistrationNo, lcVehicle);
                updateDisplay();
            }
        }