@Override
	public void notifyMessage(String sender, String message) throws RemoteException {
		if(mMessageWindows.get(sender) == null) {
			MessageWindow window = new MessageWindow(sender, this);
			window.setVisible(true);
			window.addMessage(message);
			mMessageWindows.put(sender, window);
		}
		else {
			mMessageWindows.get(sender).setVisible(true);
			mMessageWindows.get(sender).addMessage(message);
		}
	}