private void btn_return3_Click(object sender, EventArgs e)
        {
            try
            {
                if (RentalDB.DeleteRental(RentalList[ScrollPosition + 2]))
                {
                    MessageBox.Show("You have returned " + lbl_Title3.Text + ". Thank you, please come again.");
                }
                else
                {
                    MessageBox.Show("There was an error in returning your rental. Please try again or contact support.");
                }
            }
            catch (Exception)
            {
                throw;
            }

            LoadRentals();
        }