protecting pages (asking for login)

I have setup the Membership plugin. Created 2 Access Levels (Public & users). My site has 10 pages. 5 of the pages both the public and users have access to. the other 5 only users have access to. Under the public access level I out the 5 pages in Positive Rules. Under the User access level i put all 10 pages as positive rules. Now when I go to the site pages all users still have access. How do i make it so if someone goes to a page they are prompted to login (not public)?