@Override
    public void action() {
      switch (step) {
	case 0:
	  msg = new ACLMessage(ACLMessage.INFORM);
	  InventoryItem item = enterItem("Samsung USB 16GB", 50, 1);
	  msg.setContent("Name: " + item.getItemName() + "; Amount: " + item.getAmount() + "; Size: " + item.getSize() + ";");

	  for (int i = 1; i <= 1; i++) {
	    msg.addReceiver(new AID("Rack" + i, AID.ISLOCALNAME));
	  }
	  try {
	    sleep(1000);
	  } catch (InterruptedException ex) {
	    Logger.getLogger(GlobalInventoryAgent.class.getName()).log(Level.SEVERE, null, ex);
	  }
	  m_a.send(msg);
	  step = 1;

	case 1:
	  msg = m_a.receive();
	  if (msg != null) {
	    System.out.println(" - "
		+ getLocalName() + " <- "
		+ msg.getContent()
	    );
	  }
	  block();
      }
    }