} // SavePageState

        public BasePage.PageState LoadPageState <T>(BasePage page) where T : BasePage.PageState
        {
            BasePage.PageState res = null;
            if (m_PageStates.TryGetValue(page.Id, out res))
            {
                return(res as T);
            }
            return(null);
        } // LoadPageState
        } // NavigateBack

        public void SavePageState(BasePage.PageState state)
        {
            m_PageStates[state.PageId] = state;
        } // SavePageState