Logging session timeout in DB

Hi all, I am implementing a system where when a user is logged in and out that a date time is set in a database for each action for each used. We can then trace who logged in a and when. No what I would like to know is how can I record when a user closes the browser or the session expires? There is no action for these items. So what would the best way be to keep a record of this? Would the use of a cron job be appropriate? I read in the archives that the banks use javascript but I don't want to go that route. If anyone has any idea how to do this please let me know, thanks in advance. Elemental Telephone: +27 (021) 552 9799 Mobile: +27 (0) 72 441 3355 Fax: +27 (0) 86 681 5885 Web: http://www.elemental.co.za E-Mail: angelo@elemental.co.za