// Displays sending with a connected socket
// using the overload that takes a buffer, message size, and socket flags.
public static int SendReceiveTest3(Socket server)
{
    byte[] msg = Encoding.UTF8.GetBytes("This is a test");
    byte[] bytes = new byte[256];
    try 
    {
        // Blocks until send returns.
        int i = server.Send(msg, msg.Length, SocketFlags.None);
        Console.WriteLine("Sent {0} bytes.", i);
        
        // Get reply from the server.
        int byteCount = server.Receive(bytes, server.Available, 
                                           SocketFlags.None);
        if (byteCount > 0)
            Console.WriteLine(Encoding.UTF8.GetString(bytes));
    }
    catch (SocketException e)
    {
        Console.WriteLine("{0} Error code: {1}.", e.Message, e.ErrorCode);
        return (e.ErrorCode);
    }
    return 0;
}