private void editButton_Click(object sender, RoutedEventArgs e)
        {
            AddEditWindow addEditWindow = new AddEditWindow((Film)DataContext);

            addEditWindow.WindowStartupLocation = (WindowStartupLocation)1;

            addEditWindow.Show();
        }
        private void openAddWindow_Click(object sender, RoutedEventArgs e)
        {
            AddEditWindow addEditWindow = new AddEditWindow(null);

            addEditWindow.WindowStartupLocation = (WindowStartupLocation)1;

            addEditWindow.Show();
        }