private void CreateReservation_Click(object sender, RoutedEventArgs e)
{
CreateReservation newWindow = new CreateReservation();
newWindow.ShowDialog();
}
private void UpdateReservation_Click(object sender, RoutedEventArgs e)
{
IReservation reservation = (IReservation)reservationListBox.SelectedItem;
CreateReservation openReservation = new CreateReservation(reservation);
openReservation.ShowDialog();
}