every user that connect to web site will logon as anonymous user.

i want to make web site like this
1. user connect to my web site as anonymous user
2. my web site display a page with 'user name' and 'password' question
3. user fill in that 2 question and post that page back to web server
4. web server will re - login this user based on user name and password that has filled in by the user


is it possible ?

thanks in advanced

rudi