OLATResourceable syncOres = OresHelper.createOLATResourceableInstance("GroupChatJoinTask",ores.getResourceableId());
CoordinatorManager.getCoordinator().getSyncer().doInSync(syncOres, new SyncerExecutor() {
public void execute() {
if (connection != null && connection.isAuthenticated()) {
try {
RoomInfo info = MultiUserChat.getRoomInfo(connection, roomJID);
// throws an exception if the room does not exists
muc.join(nickname); // log in anonymous
addMessageListener();
addParticipationsListener();
} catch (XMPPException e) {