[Zope] Getting a specific user role

Forgive me if this has been covered before. I am implementing a login/security scheme through the use of GUF and SQL methods. My user and role information is kept in a SQL database and a user can have more than one role assigned to him/her. What I would like to do is check if a specific role has been assigned to the current user, and then display some additional menu items if that role has been assigned. I haven't been able to figure out how to get and check the roles that have been assigned to the current user. As usual, any help will be greatly appreciated. -=Brad=-