private void LoadGridData()
        {
            Action workAction = () =>
            {
                BackgroundWorker worker = new BackgroundWorker();
                worker.DoWork += (o, args) =>
                {
                    args.Result = _fService.GetAllBookings().Select(b => new
                    {
                        ID              = b.bookingID,
                        Tid             = b.totalTime,
                        Pris            = b.totalPrice,
                        Personer        = _fService.GetBookingPassengers(b.bookingID).ToList().Count,
                        Flyforbindelser = _fService.GetBookingFlights(b.bookingID).ToList().Count
                    });
                };
                worker.RunWorkerCompleted += (o, args) => { dgBookings.ItemsSource = (IEnumerable)args.Result; };
                worker.RunWorkerAsync();
            };

            dgBookings.Dispatcher.BeginInvoke(DispatcherPriority.Background, workAction);
        }