Rotating the Screen

LONG ChangeDisplaySettingsEx(
  LPCTSTR lpszDeviceName,
  LPDEVMODE lpDevMode,
  HWND hwnd,
  DWORD dwflags,
  LPVOID lParam
);

void RotateScreen( UINT position)
{
  DEVMODE  devMode = {0};

  devMode.dmSize = sizeof (devMode);
  devMode.dmFields = DM_DISPLAYQUERYORIENTATION;

  if (DISP_CHANGE_SUCCESSFUL != ChangeDisplaySettingsEx(NULL, &devMode, NULL, CDS_TEST, NULL))
  {
    RETAILMSG( 1, (TEXT("Failed to get RotationAngles")));
      return;
  }

  devMode.dmFields = DM_DISPLAYORIENTATION;
  switch ( position)
  {
    case 0:
      devMode.dmDisplayOrientation = DMDO_0;
      break;
    case 90:
      devMode.dmDisplayOrientation = DMDO_90;
      break;
    case 180:
      devMode.dmDisplayOrientation = DMDO_180;
      break;
    case 270:
      devMode.dmDisplayOrientation = DMDO_270;
      break;
  }
	
  ChangeDisplaySettingsEx(NULL,&devMode,NULL, CDS_RESET,NULL);
}