[development] Adding a query to every url

Hi Drupalfriends I'd like to add a query string to every url. If the URL is '/node/234' it should change to '/node/234&iframe=on'. I found the custom_url_rewrite_outbound function and added it to my settings.php: if (isset($_GET['iframe']) && 'on'==$_GET['iframe']) { $path .= (strpos($path, '?') !== FALSE ? '&' : '?') . 'iframe=on'; } This works fine, but the url() method, which calls custom_url_rewrite_outbound runns $path through drupal_urlencode() afterwards. This means the url changes to '/node/234%3Fiframe%3Don' which obviously does not work. Am I doing something wrong or is there another way of getting this to work? Regards Ernst