private async void LoadSeats()
 {
     try
     {
         Seats = new List <Seat>(await FlightRepository.GetAllSeatsAsync());
         SeatsWithPassengers = Seats.Where(s => s.Passenger != null);
     }
     catch (Exception e)
     {
         MessageDialog messageDialog = new MessageDialog($"Couldn't establish a connection to the database. \n{e.Message}");
         messageDialog.Commands.Add(new UICommand("Try again", new UICommandInvokedHandler(this.CommandInvokedHandler)));
         messageDialog.Commands.Add(new UICommand("Close"));
         messageDialog.DefaultCommandIndex = 0;
         messageDialog.CancelCommandIndex  = 1;
         await messageDialog.ShowAsync();
     }
 }