APEX

I have been searching the web and these forums all day for something to help me get SSO and an Apex application working to no avail. I installed the discussion forum an I am trying to modify it so that when I try to access the home page, it will redirect to our SSO/LDAP server, allow me to login, and then pass me back to the forum.

I have:


Configured Apex as a partner application with SSO
Created an Authentication Scheme called "SSO Scheme" and set the SSO Partner Application Name to "Apex Applications" which matches my sso entry in orasso.
Created a new Authorization Scheme called "SSO Users" for the user.
Set the Authorization Scheme for the application security to "SSO Users"

What do I select from the Scheme Type drop down, and what do I enter for the Expression1 on the Authorization Scheme screen?

Thanks,
Kris