public static ManualResetEvent allDone = new ManualResetEvent(false);

        private Thread yth;

        private bool listenerRun = true;

        Socket listener;

        private const int maxsocket = 10000;

        int port = 54321;

        private void buttonStart_Click(object sender, EventArgs e)

        {

            listenerRun = true;

            yth = new Thread(new ThreadStart(ListenClient));

            yth.IsBackground = true;

            yth.Start();

            this.buttonStart.Enabled = false;

            this.buttonStop.Enabled = true;

        }

        public void ListenClient()

        {

            while (listenerRun)

            {

                allDone.Reset();

                listener.BeginAccept(new AsyncCallback(AcceptCallBack), listener);

                allDone.WaitOne();

            }

        }

        private void AcceptCallBack(IAsyncResult ar)

        {

            try

            {

                allDone.Set();

                Socket sok = (Socket)ar.AsyncState;

                Socket client = sok.EndAccept(ar);

                StateObject state = new StateObject();

                state.workSocket = client;

                if(client.Available>0)

                client.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0, new AsyncCallback(ReadCallBack), state);



        &