wxCHECK_MSG( node, false, wxS("invalid index in IsEnabledTop") );
wxMenu* const menu = node->GetData();
wxCHECK_MSG( menu->m_owner, true, wxS("no menu owner?") );
wxCHECK_MSG( node, false, wxS("invalid index in IsEnabledTop") );
wxMenu* const menu = node->GetData();
wxCHECK_MSG( menu->m_owner, true, wxS("no menu owner?") );