internal void ResetParentInElementIdAttrMap(string oldVal, string newVal)
        {
            XmlElement parentElem = parent as XmlElement;

            Debug.Assert(parentElem != null);
            XmlDocument doc = parent.OwnerDocument;

            Debug.Assert(doc != null);
            doc.RemoveElementWithId(oldVal, parentElem); //add the element into the hashtable
            doc.AddElementWithId(newVal, parentElem);
        }