Jak obrócić do góry nogami ekran

procedure TForm1.Button1Click(Sender: TObject);
var
Canvas: TCanvas;
begin
Canvas:=TCanvas.Create;
try
  Canvas.Handle:=CreateDC('DISPLAY',nil,nil,nil);
  Canvas.CopyRect(Rect(0,0,Screen.Width,Screen.Height),Canvas,
    Rect(0,Screen.Height,Screen.Width,0));
finally
  Canvas.Free;
end;

end;