      *  @playerversion AIR 2.5
      *  @productversion Flex 4.5
      */
-    public var parentNavigator:ViewNavigatorBase;
+    public function get parentNavigator():ViewNavigatorBase
+    {
+        return _parentNavigator;
+    }
+    
+    /**
+     *  @private
+     */ 
+    mx_internal function setParentNavigator(value:ViewNavigatorBase):void
+    {
+        _parentNavigator = value;        
+    }
     
     //----------------------------------
     //  transitionsEnabled

    protected var _navigationStack:NavigationStack;
    
    /**
     *  The navigation stack that is being managed by the navigator.
     *  An empty navigation stack is automatically created when
     *  a navigator is created.
     * 
     *  @default null
     */ 
    public function get navigationStack():NavigationStack
    {
        return _navigationStack;
    }
    /**
     *  @private
     */ 
    public function set navigationStack(value:NavigationStack):void
    {
        if (value == null)
            _navigationStack = new NavigationStack();

    //----------------------------------
    //  parentNavigator
    //----------------------------------
    private var _parentNavigator:ViewNavigatorBase;
    
    /**
     *  The parent navigator for this navigator.
     * 
