how to get current logon user's role within portal

hi,

I can get logon user's role by coding directly against IPortalComponentRequest request, but when I move all the codes into our own par file, I don't have reference to request anymore, we do have access IResourceContext, which can be casted to IUSER, but it does not work. I can not get user's role from it. any idea how to get user's role NOT from portal component doContent? Thanks!

T.J.