diff --git a/doc/help_vol.php b/doc/help_vol.php
index 5571e43780..24e31e6f87 100644
--- a/doc/help_vol.php
+++ b/doc/help_vol.php
@@ -102,8 +102,8 @@ function email_contact($vol) {
     ";
 }
 
-$send_email = $_GET['send_email'];
-$rate = $_GET['rate'];
+$send_email = get_str2('send_email');
+$rate = get_str2('rate');
 session_set_cookie_params(86400*365);
 session_start();
 $uid = session_id();
@@ -201,7 +201,11 @@ if ($send_email) {
     echo "</td></tr></table><p>\n";
     echo "<table class=box cellpadding=8 width=100%><tr><td>";
     $rating = rating_vol_auth($vol->id, $uid);
-    if (!$rating) $rating->rating = -1;
+    if (!$rating) {
+        $rating = new StdClass;
+        $rating->rating = -1;
+        $rating->comment = "";
+    }
     show_rating($vol, $rating);
     echo "</td></tr></table>\n";