private String sendTo(String s, String ip, int port) {
		String str = null;
		try {
			Socket socket = new Socket(ip, port);
			ObjectOutputStream out = new ObjectOutputStream(
					socket.getOutputStream());
			ObjectInputStream in = new ObjectInputStream(
					socket.getInputStream());
			out.writeObject(s);
			out.flush();
			str = in.readObject().toString();
			in.close();
			out.close();
			socket.close();
		} catch (NumberFormatException e) {
			removeSlave(ip, port);
		} catch (UnknownHostException e) {
			removeSlave(ip, port);
		} catch (IOException e) {
			removeSlave(ip, port);
		} catch (ClassNotFoundException e) {
		}
		return str;
	}