private void lstSessions_SelectedIndexChanged(object sender, EventArgs e)
        {
            if (lstSessions.SelectedIndex == -1)
            {
                ClearForm.Clear(this);
            }

            else if (lstSessions.SelectedIndex > -1)
            {
                Session session = (Session)lstSessions.SelectedItem;
                dtpSessionDate.Value      = session.Date + session.Time;
                cmbMovies.SelectedValue   = session.Movie.ID;
                cmbTheatres.SelectedValue = session.MovieTheatre.MovieTheatreID;

                lstTickets.DataSource = null;
                lstTickets.DataSource = TicketDataTransaction.GetTicketDetail(session);
            }
        }