diff --git a/js/util.js b/js/util.js
index 11fc6e68a7..fe3ed74dc2 100644
--- a/js/util.js
+++ b/js/util.js
@@ -68,7 +68,7 @@ $(document).ready(function(){
                success: function(xml) {
                     var new_form = $('form.favor', xml).get(0);
                     var fav = new_form.id;
-                    var dis = dis.replace('favor', 'disfavor');
+                    var dis = fav.replace('favor', 'disfavor');
                     $('form#'+dis).replaceWith(new_form);
                     $('form#'+fav).ajaxForm(favoptions).each(addAjaxHidden);                    ;
                }};