Minor fixes to group visualizations
diff --git a/public/js/src/hint.js b/public/js/src/hint.js
index 966cc78..4f5a8b5 100644
--- a/public/js/src/hint.js
+++ b/public/js/src/hint.js
@@ -31,7 +31,7 @@
   "use strict";
 
   // Don't let events bubble up
-  if (Event.halt !== undefined) {
+  if (Event.halt === undefined) {
     Event.prototype.halt = function () {
       this.stopPropagation();
       this.preventDefault();