title: How to log out users using Facebook Connect in PHP and Zend?
body: <p>I am trying to build a Connect app using PHP and the Zend Framework.
  I also have a Zend_Auth based user authentication system.
  Now, I am able to log in using Facebook but log out is not working.</p>
  
  <p>I need to clear the Zend_Auth identity as well as remove all Facebook login info.
  What would be the best way to do this?</p>
  
  <p>I tried <code>facebook_client-&gt;expire_session()</code> and <code>facebook_client-&gt;clear_cookie_state();</code> together and also <code>facebook_client-&gt;logout($next)</code> after calling <code>Zend_Auth::getInstance()-&gt;clearIdentity()</code></p>
  
  <p>None of them seem to work.</p>