public function newsletter_unsubscribe($atts, $content)
 {
     if (isset($_REQUEST['unsubscribe'])) {
         extract(shortcode_atts(array('tabindex' => 100), $atts));
         require_once MYMAIL_DIR . '/classes/form.class.php';
         global $mymail_form;
         if (!$mymail_form) {
             $mymail_form = new mymail_form();
         }
         return do_shortcode($content) . $mymail_form->unsubscribe_form($_REQUEST['unsubscribe'], isset($_REQUEST['k']) ? $_REQUEST['k'] : '', $tabindex);
     }
 }