Feb 23, 2010 12:48 AM|Gary yang - MSFT|LINK
Now, why would AUTH_TYPE (and others) not show me any data if the site is authenticating without anonymous access?
If you hope the Browser remember the credential for the particular site. I think you should do some configuration on Browser.
Please refer to the following steps:
1. Tools->Internet Options-> Security->Custom Level->User Authentication.
2. You can enable one of the login option that provid by Browser.