I have a community-based portal (based on IBUYSPY portal) running for Internet and Intranet use. The portal is using Form authentication. All user login names and passwords of the portal are stored in a standalone SQL database. A user must login through a login page. As the portal is community-base, a user may belong to several communities with different role. For example, user A can edit in one community, but can only view for another community. Current requirement is: Intranet users want to log into the portal directly without re-input user name and password, because they have already logged into their computer with active directory authentication. Problem is: When using Form authentication only, a user can log into the portal by selecting a community name from a community dropdown list. When Windows and Form authentication are used, if a user can log into several communities, how can my ASP.NET code know the user's login name and password so that I only show the community list to select? Any idea or sample? Thanks in advance!