private void Flights_DestORBeginCombo_SelectionChanged(object sender, SelectionChangedEventArgs e) { if (Flights_DestORBeginCombo.SelectedValue == null) { Flights_RouteCombo.IsEnabled = false; return; } if (Flights_DestinationRadio.IsChecked == true) { Flights_RouteCombo.ItemsSource = Service.GetComboRoutes(workPlaceAirport, (string)Flights_DestORBeginCombo.SelectedValue).Tables[0].DefaultView; } else if (Flights_BeginingRadio.IsChecked == true) { Flights_RouteCombo.ItemsSource = Service.GetComboRoutes((string)Flights_DestORBeginCombo.SelectedValue, workPlaceAirport).Tables[0].DefaultView; } Flights_RouteCombo.SelectedIndex = 0; Flights_RouteCombo.IsEnabled = true; }