polling for socket Read.

According to the : MSDN socket polling method SelectRead returns true on 3 occasions but I'm only interested in just the one; when there's data available for reading. Is there a way to poll a socket in C# so that I read the buffer only when this condition is satisfied?
so far my method is:

Code:

private void recvMessage(ref TextBox mDest)
        {
            try
            {
                int rcount;
                if (active_connection)
                {
                    if (m_sock.Poll(-1, SelectMode.SelectRead))
                    rcount = m_sock.Receive(recvBuffer);
                    mDest.Text += Encoding.ASCII.GetString(recvBuffer);
                                        
                    Array.Clear(recvBuffer, 0, recvBuffer.Length);
                    mDest.Text += "\r\n";
                    SendMessage(mDest.Handle, WM_VSCROLL, (IntPtr)SB_BOTTOM, IntPtr.Zero);
                }
                else
                    mDest.Text = "";
            }

            catch (SocketException se)
            {
                MessageBox.Show(se.Message);
            }

        }

According to MSDN I wouldn't see why your method wouldn't work. Whenever something is true of the socket based on SelectMode.SelectRead, your thread will wakeup and call Receive.

It works, but I only want it to wake up only when there's something to read in the buffer.