Prevent possible memory leak

modules/UI/UI.js

                         input.prop("checked");
                 }
             }
+        },
+        null,
+        function () {
+            // Reset dialog reference to null to avoid memory leaks when
+            // user closed the dialog manually.
+            deviceErrorDialog = null;
         }
     );
 

modules/UI/util/MessageHandler.js

      * @param submitFunction function to be called on submit
      * @param loadedFunction function to be called after the prompt is fully
      *        loaded
+     * @param closeFunction function to be called on dialog close
      */
     openDialog: function (titleString, msgString, persistent, buttons,
-                              submitFunction, loadedFunction) {
+                              submitFunction, loadedFunction, closeFunction) {
         if (!popupEnabled)
             return;
 
             buttons: buttons,
             defaultButton: 1,
             loaded: loadedFunction,
-            submit: submitFunction
+            submit: submitFunction,
+            close: closeFunction
         };
+
         if (persistent) {
             args.closeText = '';
         }
+        
         return new Impromptu(msgString, args);
     },