bool ControlPoint::unsubscribe(Service *service) {
  SubscriptionRequest subReq;
  subReq.setUnsubscribeRequest(service);
  if (Debug::isOn() == true)
    subReq.print();  
  SubscriptionResponse *subRes = subReq.post();
  if (Debug::isOn() == true)
    subRes->print();  
  if (subRes->isSuccessful() == true) {
    service->clearSID();
    return true;
  }
  return false;
}