#region main
        private void Form1_Load(object sender, EventArgs e)
        {
            try
            {
            Connect("10.81.0.102", "#10", 4001);
            }
            catch (Exception ex)
            {
              textBox1.Text =  ex.ToString();
            }

        }
        #endregion


        #region client
        static void Connect(String server, String message, Int32 port )
        {
            try
            {
                // Create a TcpClient.
                // Note, for this client to work you need to have a TcpServer 
                // connected to the same address as specified by the server, port
                // combination.
                TcpClient client = new TcpClient(server, port);

                // Translate the passed message into ASCII and store it as a Byte array.
               // Byte[] data = System.Text.Encoding.ASCII.GetBytes(message);
                Byte[] data = Encoding.UTF8.GetBytes(message);
                // Get a client stream for reading and writing.
                //  Stream stream = client.GetStream();

                NetworkStream stream = client.GetStream();

                // Send the message to the connected TcpServer. 
                stream.Write(data, 0, data.Length);

               MessageBox.Show("Sent: " +  message);

                // Receive the TcpServer.response.

                // Buffer to store the response bytes.
                data = new Byte[256];

                // String to store the response ASCII representation.
                String responseData = String.Empty;

                // Read the first batch of the TcpServer response bytes.
                Int32 bytes = stream.Read(data, 0, data.Length);
                responseData = System.Text.Encoding.ASCII.GetString(data, 0, bytes);
                MessageBox.Show("Received: {0}"+ responseData);

                // Close everything.
                stream.Close();
                client.Close();
            }
            catch (ArgumentNullException e)
            {
               
                MessageBox.Show("ArgumentNullException: {0}"+ e.ToString());
            }
            catch (SocketException e)
            {
                MessageBox.Show("SocketException: {0}"+ e.ToString());
            }

            MessageBox.Show("\n Press Enter to continue...");
            
        }
        #endregion

Connect("10.81.0.102", "#10\r", 4001);