Fix prototype errors in chrome

Author: empiricompany

js/prototype/prototype.js

@@ -2173,7 +2173,9 @@ Ajax.PeriodicalUpdater = Class.create(Ajax.Base, {
 
   function remove(element) {
     element = $(element);
-    element.parentNode.removeChild(element);
+    if (element.parentNode) {
+      element.parentNode.removeChild(element);
+    }
     return element;
   }