private void lstTractors_SelectedIndexChanged(object sender, EventArgs e)
        {
            // lstTractors listbox is an exact representation of my generic
            // tractor list. I will use the index of the selected item
            // to retrieve the tractor object from the generic list.
            // Put the tractor details onto textboxes
            // Will also put the tractor registration number into the combobox cboTractors

            int     indexTemp      = lstTractors.SelectedIndex;
            Tractor currentTractor = garage.ElementAt(indexTemp);

            cboTractors.Items.Add(currentTractor.RegistrationNumber);
            txtRegNum.Text = currentTractor.RegistrationNumber;
            txtMake.Text   = currentTractor.Make;
            txtModel.Text  = currentTractor.Model;
            txtPrice.Text  = (currentTractor.Price.ToString("c"));
            // highlighting the contains method...
            if (garage.Contains(currentTractor))
            {
                int     whereItis     = garage.IndexOf(currentTractor);
                Tractor searchTractor = garage.ElementAt(whereItis);
                // display the tractor
            }
            else
            {
                // not found
            }
        }
        private void frmListsEtc_Load(object sender, EventArgs e)
        {
            Tractor t1 = new Tractor("88MO1244", "Ford", "4400", 12000);
            Tractor t2 = new Tractor("76DL5555", "Ford", "3600", 14000);
            Tractor t3 = new Tractor("94SO5678", "Massey Ferguson", "365", 5000);
            Tractor t4 = new Tractor("76RN4455", "David Brown", "895", 2500);

            garage.Add(t1);
            garage.Add(t2);
            garage.Add(t3);
            garage.Add(t4);

            // Place each tractor in the garage onto lstTractors ListBox
            foreach (Tractor stockNum in garage)
            {
                lstTractors.Items.Add(stockNum);
            }
        }