((Spellbook_gump *) parent)->change_page(leftright ? 1 : -1);
Spellbook_gump *sgump = (Spellbook_gump *) parent; int bmpage = sgump->book->bookmark/8;  if (bmpage >= 0 && bmpage != sgump->page) sgump->change_page(bmpage - sgump->page);
void Page_button::activate	(	)	{	((Spellbook_gump *) parent)->change_page(leftright ? 1 : -1);	}