Support for regular drupal success message rather than new page

It would be nice to have support for a regular drupal success message rather than having to show a whole new page. Allowing this option makes for nice integration with AJAX forms. I have created a patch to get this working on my site. Patch is against 6.x-2.3:

--- webform.module.old  2008-10-14 18:51:42.000000000 -0300
+++ webform.module      2008-11-25 13:05:13.000000000 -0400
@@ -649,7 +649,7 @@
   $form['webform']['settings']['confirmation'] = array(
     '#type' => 'textarea',
     '#title' => t("Confirmation message or redirect URL"),
-    '#description' => t("Message to be shown upon successful submission or a path to a redirect page. Redirect pages must start with <em>http://</em> for external sites or <em>internal:</em> for an internal path. i.e. <em>http://www.example.com</em> or <em>internal:node/10</em>"),
+    '#description' => t("Message to be shown upon successful submission or a path to a redirect page. Preface message with <em>message:</em> for a simple message that does not require a page refresh. Redirect pages must start with <em>http://</em> for external sites or <em>internal:</em> for an internal path. i.e. <em>http://www.example.com</em> or <em>internal:node/10</em>"),
     '#default_value' => $node->webform['confirmation'],
     '#cols' => 40,
     '#rows' => 10,
@@ -1814,6 +1814,11 @@
     $path = preg_replace('/^internal:/', '', $node->webform['confirmation']);
     $redirect = array(trim($path), 'sid='. $sid);
   }
+  elseif (preg_match('/^message:/', $node->webform['confirmation'])) {
+    $message = preg_replace('/^message:/', '', $node->webform['confirmation']);
+    drupal_set_message(t($message));
+    $redirect = NULL;
+  }
   else {
     $redirect = array('node/'. $node->nid .'/done', 'sid='. $sid);
   }