title: How to delete our application session when user logout from facebook canvas page?
body: <p>I've a situation where i create my own session variables while users log in to my application.
  And whenever my users log out from my application , i clear my own sessions and then call the fb logout also.. </p>
  
  <pre><code>$facebook = new Facebook(array(
  'appId'  =&gt; $this-&gt;key,
  'secret' =&gt; $this-&gt;secret,
  ));
  $logoutUrl = $facebook-&gt;getLogoutUrl(array('next' =&gt; my url));
  Yii::app()-&gt;request-&gt;redirect($logoutUrl);
  </code></pre>
  
  <p>But while my users go to the application through canvas, and if they logout from facebook itself then i couldn't track when they logged out of the facebook. So my session values remain there and when i login again with some other user, the old session in alive.</p>
  
  <p>how can i handle this? Is there any way to find out the event of users logging out from facebook and i can remove my session also?</p>