NetworkStream from a Socket

using System;
using System.IO;
using System.Net.Sockets ;

class MainClass
{
public static void Main()
{
TcpListener tcpl = new TcpListener(9999);
tcpl.Start();

for (;;)
{
Socket newSocket = tcpl.AcceptSocket();
if (newSocket.Connected)
{
NetworkStream ns = new NetworkStream(newSocket);

byte[] buf = {1,2,3,4,5,6,7,8,9};
ns.Write(buf, 0, 9);

ns.Flush();
ns.Close();

}
newSocket.Close();
break;

}
}

}