public void receive() {
		String[] data = client.receiveMessage();
		
		if (data == null) return;
				
		/* ICMP message */
		if (data.length == 3) {
			int type = Integer.parseInt(data[0]);
			String src = data[1];
			String message = "";
			
			if (type == ICMP_Header.UNREACHABLE) {
				String badHost = data[2];
				message = "-- ICMP from <" + src + "> Unknown host: " +
						badHost;
			} else if (type == ICMP_Header.TIME_EXCEEDED) {
				message = "-- ICMP from <" + src + "> TTL expired";
			}
			
			textArea.append(message + "\n");
			return;
		} 
		
		String src = data[0];
		String message = data[1];
		
		textArea.append("- Got from <" + src + "> - " + message + "\n");
	}