public Page1()
        {
            InitializeComponent();

            MyDataContext dboperator = new MyDataContext(CurrentUser.connectionString);


            var flights = from fl in dboperator.flights
                          join airc in dboperator.airlines on fl.AirlineID equals airc.AirlineID
                          join air in dboperator.aircrafts on fl.AircraftID equals air.AircraftID
                          select new
            {
                fl.ArrivalCity,
                fl.ArrivalTime,
                fl.DepartureTime,
                fl.DepatureCity,
                fl.FlightNumber,
                airc.AirlineName,
                fl.FlightID,
                air.AircraftModel,
                air.SideNumber
            };

            foreach (var item in flights)
            {
                DataGridFlights.Items.Add(item);
            }



            _ComboBoxHours   = CurrentUser.LoadComboBoxHours(_ComboBoxHours);
            _ComboBoxMinutes = CurrentUser.LoadComboBoxMinutes(_ComboBoxMinutes);
            CurrentUser.LoadComboBoxSideNumberandAirline(ref _ComboBoxAirlineName, ref _ComboBoxAirlineNameINV, ref _ComboBoxSideNumber, ref _ComboBoxSideNumberINV);
        }
 //Добавить рейс
 private void ButtonClick_AddFlight(object sender, RoutedEventArgs e)
 {
     TextBlockMessgeAddFlight.Visibility = Visibility.Hidden;
     ClearValue();
     CurrentUser.LoadComboBoxSideNumberandAirline(ref _ComboBoxAirlineName, ref _ComboBoxAirlineNameINV, ref _ComboBoxSideNumber, ref _ComboBoxSideNumberINV);
 }