I have a PortalSiteMapProvider which I am using for Normal navigation across my sites. My site has many areas ( webs ). Now with the help of Navigation changer, I am making some nodes hidden. Now I need to write code to get all those nodes which are visible. I am not able to find property where I can make that decision.

So my questions are
1. What property does get modified when I hide a link by navigation changer.
2. How I can display only the visible nodes (I am making use of IsVisible property of PortalSiteMapNode, but its not working ).

I am using this code as my base
stackoverflow.com/.../creating-sharepoint-moss-sitemap