2 Responses

1. Cookie redirect
   One way would be to use a cookie redirect

   see: http://javascript.internet.com/cookies/cookie-redirect.html

2. Alternative to Cookie
   In our experience, simpler is better in the long run. Why not create an index of bookmarks at the front of the package as a contents list?

   Modules previously studied will (dependent on link colours and history clearing) be dimmed and the learner accesses the next in line (or the last selected to regain continuity).

   I appreciate that this is a low-tech solution that may not suit the structural design of what you are using, but it may be useful to you elsewhere.