According to fairvote.org (yet not updated on wikipedia), Alabama is now a closed primary state. Please checked to see if there have been any updates for your state by clicking http://www.fairvote.org/congressional-primaries-open-closed-... . The list was updated by fairvote on November 2011.
UPDATE!! Further research Alabama laws, Alabama declares itself "closed", but actually operates like an open primary. A little confusion, but there have been no recent changes on Alabama's primary voting.