private void editPromotionButton_Click(object sender, EventArgs e)
 {
     if (promotionsListBox.SelectedItem != null)
     {
         AddEditPromotionForm editPromotionForm = new AddEditPromotionForm((Promotion)promotionsListBox.SelectedItem, EDIT_PROMOTION, getMakesList(), this);
         editPromotionForm.Show();
     }
 }
        private void addPromotionsButton_Click(object sender, EventArgs e)
        {
            AddEditPromotionForm addPromotionForm = new AddEditPromotionForm(null, ADD_PROMOTION, getMakesList(), this);

            addPromotionForm.Show();
        }