title: joomla 2.5.8 destroy all started sessions in tab (guest and user) on logout, and start new guest session only
body: <p>Welcome.
  I'm on joomla 2.5.8 &amp; virtuemart 2.0.16.
  The problem exist on all templates, as I travel through browsers, I find that safari and chrome keeps data from forms after logout i.e. I'm log in to review and change my shoper datas I'm saving them and log out (I have made some changes that the datas are not keept in firefox and opera - but about that later). After logout I click back button once, twice and voila the data cames back (just to view not to save but did, adress, phone... that should'n have place).</p>
  <p>I'm not so good in php and javascript. I found that session for user and guest are two diferent sessions (guest for view and user for edit and save - in my case). so when user is loging out guest stil can read previons logged in user. I check that if I hit ctrl+r in chrome &amp; safari (on form with recovered datas) that datas disappears (the form is displaying again but without any datas - and all other trials, saving, canceling etc.. , are ended on registration or login page). To get this effect I create autentyfikacja.php :</p>
  <pre><code>    &lt;?php /*Funkcja sprawdzająca autentycznosc użytkownika, gość - user*/ ?&gt;
  
  
  &lt;?php
  if(!function_exists('CheckState'))
  {
      function CheckState()
      {
          $uzytkownik=&amp;JFactory::getUser();
          if(!$uzytkownik-&gt;guest) return true;
  
      else return false;
  
      }
  }
  ?&gt;
  </code></pre>
  <p>and include it to some files with this value</p>
  <pre><code>include 'autentyfikacja.php';
  $zarejestruj=JRoute::_('index.php?option=com_users&amp;view=login', $this-&gt;useXHTML, $this-&gt;useSSL);
  if (!CheckState())
  {
    //wywal niezarejestrowanego na strone rejestracji
    JRequest::checkToken('post') or die( header(&quot;location: $zarejestruj&quot;) );
    exit;  //this one I even don't know if it's needed and why in some casses but it works:)
  } else 
  </code></pre>
  <p>after that I get firefox, opera, and internet explorer working - chrome and safari still don't. why?</p>
  <p>after deleting cookies in chrome on session (all mydomain cookie) i found that works like i.e. internet explorer, but that should do the session.php file on public function destroy() (I think)</p>
  <p>I place a movie 9min explaining problem IT IS NOT ADVERTISE it's just my first movie, but it's with polish comments (if anglish needed I will record next :) - that was for my friend he give up)</p>
  <p><a href="http://esteart.home.pl/Untitled.mp4" rel="nofollow noreferrer">problematic movie</a></p>
  <p>my supose is to kill and make new both sessions on logout and logout only! (guest and user - to make effect like logout for user and ctrl+r for guest, but only in logout case). How to and where ??? in session.php? or some diferent file from templte?</p>
  <p>Better in autentyfikacja.php , made by my own :) .</p>
  <p>Any idea would by nice I'm starting to give up too. After week.</p>
  <p>To see it by Your own there is login: demo and pass: demo
  site <a href="http://www.esteart.eu" rel="nofollow noreferrer">esteart.eu</a>  As I say is not advertise, target and name would be diferent, after finish.</p>
  <p>may be set guest token same as user after login? how?</p>