private void frm_reser_vol_Load(object sender, EventArgs e)
        {
            ReservationADO res = new ReservationADO();

            res.load_passager(combo_pass);
            res.load_vol(combo_vol);
        }
        private void button1_Click(object sender, EventArgs e)
        {
            Connexion       c  = new Connexion();
            OleDbConnection cn = c.connect();

            cn.Open();
            Reservation    r   = new Reservation(12, date_res.Value, Int32.Parse(num_pass), Int32.Parse(num_vol));
            ReservationADO res = new ReservationADO();

            res.reserver(r, cn);
        }