procedure TSDIAppForm.ImageLibMouseDown(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
var
  midx: Integer=28;
  midy: Integer=29;
  r: Integer=24;
begin
  if Abs(midx-X)+Abs(midy-Y)=<r then
      MessageBox(Application.Handle,'Click',MB_OK,0);
end;