authlogic and controlling the resources users can access

question re authlogic, all set up but now i'd ike to control access to a
resource so only users who own that resource can control it, I figure I
put this in the Advert controller - is this approach sound ?

http://pastie.org/1069488

I also specify that an admin (just a boolean controlled user) can edit
everything... is it good ?

User, has many Adverts and Advert belongs to a User

Just about to implement this in a new app and wanted a second opinion.

cheers

bb

Is this approach sound?