Как установить разрешение экрана?

Code:

function SetFullscreenMode:Boolean;

var DeviceMode : TDevMode;

begin

with DeviceMode do begin

dmSize:=SizeOf(DeviceMode);

dmBitsPerPel:=16;

dmPelsWidth:=640;

dmPelsHeight:=480;

dmFields:=DM_BITSPERPEL or DM_PELSWIDTH or DM_PELSHEIGHT;

result:=False;

if ChangeDisplaySettings(DeviceMode,CDS_TEST or CDS_FULLSCREEN) <> DISP_CHANGE_SUCCESSFUL

  then Exit;

Result:=ChangeDisplaySettings(DeviceMode,CDS_FULLSCREEN) = DISP_CHANGE_SUCCESSFUL;

end;

end;

procedure RestoreDefaultMode;

var T : TDevMode absolute 0;

begin

ChangeDisplaySettings(T,CDS_FULLSCREEN);

end;

procedure TForm1.Button1Click(Sender: TObject);

begin

if setFullScreenMode then begin

sleep(7000);

RestoreDefaultMode;

end;

end;