Socket closed

I posted this a while ago, but I can't seem to get an answer or find one elsewhere. Anyway, how does one know when a NetworkStream or TcpClient's connection is closed? Right now I'm doing something like this:

Code:

---

try
{
    while(_nstream != null)
    {
      //read / write
    }
}
catch
{
  // socket closed?
}

---

but this never seems to work. the connection will be terminated by the remote host, but you wouldn't know it... any suggestions?

look over pscode.com they have plenty of examples about that