private void CheckAvailable_Click(object sender, RoutedEventArgs e)
        {
            Button button = sender as Button;

            currentRequest = button.DataContext as BO.GuestRequest;
            availableHU    = bl.CheckForAvailableHostingUnit(currentRequest.EntryDate, bl.PassedDays(currentRequest.EntryDate, currentRequest.ReleaseDate)).ToList().FindAll(x => x.Owner == hostID);
            AvailableHUList.ItemsSource = availableHU;
            if (availableHU.Any())
            {
                AvailableHUTextBox.Background = Brushes.Green;
            }
            else
            {
                AvailableHUTextBox.Background = Brushes.Red;
            }
            AvailbeHUGrid.Visibility = Visibility.Visible;
        }