title: Inconsistent browser caching of session variables - any solutions?
body: <p>Why are my session variables being dropped here?</p>
  
  <p>I submit a form using the submit button and create session variables of the values to allow them to be carried to other pages. All's fine. If I now move back and forward between the form and form handler using the browser buttons (as some user sometime will probably do) Firefox and Opera recalls the session variables and can populate the form handler. IE and Safari however don't. What can I do about it?</p>
  
  <p>Firefox would demonstrate the problem if I hadn't inserted the following in the header file earlier this morning:</p>
  
  <pre><code>header("Cache-Control: no-cache");
  header("Expires: -1");
  </code></pre>
  
  <p>I've read that the second header line - <code>header("Expires: -1");</code> - should also be the fix for IE but that seems not to be the case. IE8 / Safari still show the problem. Opera doesn't need this at all. If this is a reload problem what do I need to add to the header to force IE and Safari to reload?</p>
  
  <p>Thanks</p>