Odświeżanie monitora

W jaki sposób za pomoca delphi zmienic odświeżanie monitora ;) ?

www.torry.net

function NewRes(XRes, YRes: DWORD; Frequency: Cardinal): Integer;
var
  DevMode: TDeviceMode;
begin
  EnumDisplaySettings(nil, 0, DevMode);
  DevMode.dmFields := DM_PELSWIDTH or DM_PELSHEIGHT or DM_DISPLAYFREQUENCY;
  DevMode.dmPelsWidth := XRes;
  DevMode.dmPelsHeight := YRes;
  DevMode.dmDisplayFrequency := Frequency;
  Result := ChangeDisplaySettings(DevMode, 0);
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
  if NewRes(1280, 1024, 85) = DISP_CHANGE_SUCCESSFUL then
    ShowMessage('Resolution changed!');
end