How to check if user is currently logged in Windows?

Using Coldfusion 8,

how can I check whether window user is currently logged in?

I know, I can use cgi.auth_user variable (domain\username ), however is it always reliable to use?

if not, what other ways to check?

IIRC, cgi.auth_user shows the username of a user authenticated via basic authentication. I don't think it supports windows domain connections. Assuming that you are on a windows domain, that should be easy to test -- just dump the cgi scope.