Custom SiteMapProvider. Please, need some help.

[shapper]

Hello,

I need to create a custom SiteMapProvider.
I searched in Google for examples but I am still completly lost.

The custom SiteMapProvider I need to create is exactly the same as the
Asp.Net SiteMapProvider:

The only difference is:

> The provider should select only the XML nodes which custom

attribute Visible = "True".

I think this would be a small change to the default SiteMap Provider of
Asp.Net 2.0.
Could someone help me out?

I am completly lost. Most sitemap providers are found work with SQL
databases.
And even those made me completly confused about the code.

Thanks,
Miguel