      */
     override public function addChild(child:DisplayObject):DisplayObject
     {
-        throw(new Error("This method is not available in this class.  Please consult the documentation."));
+        throw(new Error(resourceManager.getString("components", "methodUnavailable")));
     }
     
     /**

            maxIndex++;
            
        if (index < 0 || index > maxIndex)
            throw new RangeError("Index " + index + " is out of range");
    }
 
    /**

    public function addElementAt(element:IVisualElement, index:int):IVisualElement
    {
        if (element == this)
            throw new ArgumentError(resourceManager.getString("components", "cannotAddYourselfAsYourChild"));
            
        // check for RangeError:
        checkForRangeError(index, true);
