public void TryToBook()
 {
     try
     {
         NoSelectedIndex(SommerhusIndex);
         Sommerhus temp = SommerhusMatch[SommerhusIndex];
         BonDialog = new MessageDialog("Er du sikker på at du vil booke sommerhuset i " + temp.Beliggenhed + " fra: " + FraDato.ToString("d") + " til: " + TilDato.ToString("d"));
         BonDialog.Commands.Add(new UICommand("JA", command =>
         {
             BookingRegister.CheckIfBooking(Pro, temp, FraDato, TilDato);
             Dialog.Show("Booking gennemført");
             BookingPersistency.SaveBookingAsJsonAsync(BookingRegister.Bookings);
         }));
         BonDialog.Commands.Add(new UICommand("NEJ", command => { }));
         BonDialog.ShowAsync();
     }
     catch (ArgumentOutOfRangeException)
     {
         Dialog.Show("Du har ikke valgt noget sommerhus at booke");
     }
     catch (NullReferenceException ex)
     {
         Dialog.Show(ex.Message);
     }
     catch (ArgumentException ex)
     {
         Dialog.Show(ex.Message);
     }
 }
        public BookingSystem()
        {
            Sommerhuse        = new ObservableCollection <Sommerhus>();
            PersoneriCombobox = new ObservableCollection <int>();
            VærelserICombobox = new ObservableCollection <int>();



            //InitSommerhus();

            ProfileRegister = new ProfileRegister();
            KundeRegister   = new KundeRegister();
            AdminRegister   = new AdminRegister();
            BookingRegister = new BookingRegister();
            FavoritRegister = new FavoritRegister();

            LoadKunder();
            LoadProfiles();
            LoadSommerhuse();
            LoadBookings();
            LoadFavorits();


            _navigationService     = new NavigationService();
            NavToMainSystemCommand = new RelayCommand(CheckLoginInformationAndNavigate);

            AddProfileWithCustomerCommand = new RelayCommand(AddCustomerWithProfile);
            NavToOretProfilCommand        = new RelayCommand(() =>
            {
                _navigationService.Navigate(typeof(OpretProfil));
            });
            SendEmailCommand = new RelayCommand(() =>
            {
                Dialog.Show("Logininformationer er sendt til din email");
            });
            NavToOpretSommerhus = new RelayCommand(() =>
            {
                _navigationService.Navigate(typeof(OpretSommerhus));
            });
            NavToListSommerhus = new RelayCommand(() =>
            {
                try
                {
                    CheckComboboxValue(SelectedAntalPersoner, SelectedAntalVærelser);
                    CheckTime(FraDato, TilDato);
                    MatchAfSommerhus();
                    _navigationService.Navigate(typeof(SommerhusListe));
                }
                catch (ArgumentException ex)
                {
                    Dialog.Show(ex.Message);
                }
            });
            LogudCommand = new RelayCommand(() =>
            {
                _navigationService.Navigate(typeof(Login));
            });
            DeleteKundeCommand = new RelayCommand(DeleteKundeFromListe);

            AddSommerhusCommand = new RelayCommand(AddSommerhus);


            ShowPageOmOsCommand      = new RelayCommand(ShowOmOs);
            ShowPageKontaktOsCommand = new RelayCommand(ShowKontaktOs);
            BookingCommand           = new RelayCommand(TryToBook);
            NavToMinProfilCommand    = new RelayCommand(() =>
            {
                MatchFavorites();
                _navigationService.Navigate(typeof(MinProfil));
            });
            AddFavoritCommand = new RelayCommand(AddToFavorites);
        }