UDP communication

I'm busy making an webbased udp communications application for communication with a hardware solution, for now everything works fine the messages i send from my webform arriving at the terminal and the terminals is responding. I can see the udp packages because i've installed ethereal.

Now i want the reply message from the udp message i send be placed in a label txtPing, below is my source code but how can i realize this.



public class UDPListener

private const int listenPort = 2002;

private static void StartListener()

UdpClient listener = new UdpClient(listenPort);

IPEndPoint groupEP = new IPEndPoint(IPAddress.Any, listenPort);

try

byte[] bytes = listener.Receive(ref groupEP);

Console.WriteLine("Received broadcast from {0} :\n {1}\n",

Encoding.ASCII.GetString(bytes, 0, bytes.Length));

catch (Exception e)

Console.WriteLine(e.ToString());

public partial class _Default : System.Web.UI.Page

protected void Page_Load(object sender, EventArgs e)

protected void Button1_Click(object sender, EventArgs e)

string ip = Ipadres1.Text;

string Poort = Poort1.Text;

int SendPoort = Convert.ToInt32(Poort);

UdpClient udpClient = new UdpClient();

// Bericht verzenden.

Byte[] sendBytes = Encoding.ASCII.GetBytes(Command1.Text + (char)13);

try

catch (Exception error)

Console.WriteLine(error.ToString());

protected void Button2_Click(object sender, EventArgs e)

string ip = Ipadres1.Text;

lblStatus.Text = null;

txtPing.Text = null;

try

Ping ping = new Ping();

PingReply pingreply = ping.Send(Ipadres1.Text);

txtPing.Text += "
   Ip adres : " + pingreply.Address + "\r
";

txtPing.Text += "   Tijd : " + pingreply.RoundtripTime + " ms \r
";

txtPing.Text += "   TTL (Time To Live): " + pingreply.Options.Ttl + " ms \r
";

txtPing.Text += "   Buffer Size: " + pingreply.Buffer.Length.ToString() + " bytes \r";

catch (Exception err)