private void buttonEnter_Click(object sender, EventArgs e) { if (bh.bookingExists(id_booking)) { this.id_booking = Convert.ToInt32(textBoxCode.Text); if (comboBox.SelectedValue.ToString() == "Check-In") { CheckIn frm = new CheckIn(); frm.setIdBooking(id_booking); frm.Show(); this.Hide(); } else { CheckOut frm = new CheckOut(this); frm.setIdBooking(id_booking); frm.Show(); this.Hide(); } } else { MessageBox.Show("Booking Number does not exists"); } }