assuming you work on one cv at a time, it makes sense to store current skills in a session. AS such, a the CurrentSkills session variable stars with the application as an empty list of ints, which will be ids for the skills. Also i found a session helper thing which makes dealing with sessions a little easier and futureproof by JM Alarcon at  http://www.campusmvp.net/blog/how-to-manage-session-variables-like-a-pro