protected void onTick() {
		ACLMessage msg = myAgent.receive();
		if (msg != null && msg.getPerformative() == ACLMessage.ACCEPT_PROPOSAL)
			myAgent.served.add(msg.getConversationId());
		
		String food = myAgent.food.get(RandomUtils.range(0, myAgent.food.size() - 1));
		String drink = myAgent.drink.get(RandomUtils.range(0, myAgent.drink.size() - 1));
		switch (f_or_d) {
		case 0:
			if(!DFServiceUtils.sendRandomMsg(myAgent, food, Constants.FOOD))
				myAgent.doDelete();
			break;
		case 1:
			if(!DFServiceUtils.sendRandomMsg(myAgent, drink, Constants.DRINK))
				myAgent.doDelete();
			break;
		case 2:
			DFServiceUtils.sendMsgToService(myAgent, "Quieres " + food + "?", 
					Constants.HOST_SERVICE, Constants.FOOD, ACLMessage.REJECT_PROPOSAL);
			break;
		}
		f_or_d = (f_or_d + 1) % 3;
	}