getNavigator

printf("\nGetting the window...\n");
  nsCOMPtr<nsIDOMWindow> window = GetWindow();

  printf("\nGetting the navigator...\n");
  nsCOMPtr<nsIDOMNavigator> navigator;
  window->GetNavigator(getter_AddRefs(navigator));
  //NS_ENSURE_ARG_POINTER(navigator);

  printf("\nGetting the pointer...\n");
  nsCOMPtr<nsIDOMMouseLockable> pointer;
  navigator->GetPointer(getter_AddRefs(pointer));
  //NS_ENSURE_ARG_POINTER(pointer);
  if (pointer) {
    printf("\npointer exists, now unlocking  the mouse\n");
    pointer->Unlock();
  }