title: Whats the easiest way to determine if a user is online? (PHP/MYSQL)
body: <p>Is there a way I can piggy back sessions to know if the user is online?</p>
  
  <p>I.e: use logs on, I set a $_SESSION variable, user times out- cookie Garbage collector updates the database to update their status as offline.</p>
  
  <p><code>EDIT:</code> I want a solution that does not involve times or dates.  I want something to ride on sessions or something similar.  Guessing if someone is online is not good enough for what I need.</p>