Items einer ListBox mittels DragDrop verschieben?

[oki]

Delphi-Quellcode:

procedure TForm1.ListBox1DragDrop(Sender, Source: TObject; X, Y: Integer);
var TargetIndex : Integer;
begin
  if (Sender is TListBox) and (Source is TListBox) then
  begin
    with Sender as TListBox do
    begin
      TargetIndex := ItemAtPos(Point(X, Y), True);
      if (ItemIndex > -1) and (ItemIndex > -1) then
      begin
        Items.Move(ItemIndex, TargetIndex);
      end;
    end;
    ListBox2.Items.Assign(ListBox1.Items);
  end;
end;

Ich tu mich heute aber schwer