public void ListPlayersInRoom(string roomName, participantsDelegate callback)
    {
        _participantsDelegate = callback;
        DiscoInfoIq discoIq = new DiscoInfoIq(IqType.get);
        discoIq.To = makeMucJid(roomName);
        _xmppCon.IqGrabber.SendIq(discoIq, new IqCB(ListPlayersInRoomCallback));
    }

    private void ListPlayersInRoomCallback(object sender, IQ iq, object data)
    {
        DiscoItems items = iq.Query as DiscoItems;
        if (items == null)
            return;

        DiscoItem[] players = items.GetDiscoItems();
        foreach (DiscoItem player in players)
        {
            _participantsDelegate(iq.From.User, player.Jid.User);
        }
    }

    private Jid makeMucJid(string room)
    {
        return new Jid(room + "@conference." + _domain);
    }