private void MoveDownButton_Click(object sender, RoutedEventArgs e)
{
int selidx = packagelistbox.SelectedIndex;
if (selidx >= 0 && selidx < packagelistbox.Items.Count - 1) // if no item selected OR not the last item
{
var itm = packagelistbox.SelectedItem;
packagelistbox.Items.Remove(itm);
packagelistbox.Items.Insert(selidx + 1, itm);
packagelistbox.SelectedItem = itm;
//ApplyPackageButton.IsEnabled = true;
}
}