private void initBookmark() {
    int number = BookmarkDatabase.getInstance().getBookmarks(container.getName()).size();
    final ListView bookmark = (ListView) findViewById(R.id.bookmark);
    String bookmarks = "Bookmarks (" + number + ")";
    String[] bookmark_values = new String[] {bookmarks};

    Class<?>[] classList = new Class<?>[] {BookmarksActivity.class};
    this.setListViewContent(bookmark, bookmark_values, classList);
  }
  @Override
  public void onBackPressed() {
    super.onBackPressed();
    if (container != null) {
      ContainerHolder.getInstance().remove(container.getNativePtr());

      // Close book (need to figure out if this is the best place...)
      EPub3.closeBook(container);
    }
  }