public boolean changeUser(String receiver) {
		try {
			for(String user : _remoteObj.getAllUser()) {
				if(user.equalsIgnoreCase(receiver)) {
					_receiver = receiver;
					return true;
				}
			}
		} catch(RemoteException ex) {
			if(connect())
				return changeUser(receiver);
			System.out.println("Cannot get User list");
		}
		_receiver = _username;
		return false;
	}