private void btnUpdate_Click(object sender, EventArgs e)
        {
            if (dtpDate.Value.Date < DateTime.Now.Date)
            {
                MessageBox.Show("Date of new flight can only after today", "Message", MessageBoxButtons.OK, MessageBoxIcon.Error);
                return;
            }

            if (dtpDate.Value.Date == DateTime.Now.Date && dtpTime.Value.TimeOfDay <= DateTime.Now.TimeOfDay)
            {
                MessageBox.Show("Time of flight can only after now", "Message", MessageBoxButtons.OK, MessageBoxIcon.Error);
                return;
            }

            if (Flight.Schedule.Date != dtpDate.Value.Date)
            {
                if (Db.Context.Schedules.Where(t => t.Date == dtpDate.Value.Date && t.FlightNumber == Flight.Schedule.FlightNumber).FirstOrDefault() != null)
                {
                    MessageBox.Show($"Duplicate schedule with date {dtpDate.Value.ToString("dd/MM/yyyy")} and flight number {Flight.Schedule.FlightNumber}", "Message", MessageBoxButtons.OK, MessageBoxIcon.Error);
                    return;
                }
            }

            Flight.Schedule.Date         = dtpDate.Value.Date;
            Flight.Schedule.Time         = dtpTime.Value.TimeOfDay;
            Flight.Schedule.EconomyPrice = (int)nudPrice.Value;

            Db.Context.SaveChanges();
            ManageWindow.LoadFlights();
            MessageBox.Show("Edit flight Successful", "Message", MessageBoxButtons.OK, MessageBoxIcon.Information);
            this.Close();
        }
 private void btnSave_Click(object sender, RoutedEventArgs e)
 {
     Flight.Schedule.Crew = crews[cbCrews.SelectedIndex];
     Db.Context.SaveChanges();
     ManageWindow.LoadFlights();
     MessageBox.Show("Set up crew successful!", "Message", MessageBoxButton.OK, MessageBoxImage.Information);
     this.Close();
 }