while (true)
{
    byte[] btServerReceive = new byte[256];
    TcpClient tcpclient = tcp.AcceptTcpClient();
    NetworkStream ns = tcpclient.GetStream();
    int intReceiveLength = ns.Read(btServerReceive, 0, btServerReceive.Length);

    string recv = Encoding.GetEncoding("GB2312").GetString(btServerReceive) + "_01";
    tcpclient.Close();
    MessageBox.Show(recv.ToString());

    // Create a new thread to handle the data associate with recv
    Thread sendUpThread = new Thread(new ParameterizedThreadStart(SendThread));
    sendUpThread.Start(recv);
}