reset all logged in users after they shutdown their consoled

i have list of student who have Nintendo DSs, and they should log in my website to solve some sheets (by using DS Opera browser), when they logged in , (status filed at my DB will change from 0 to 1),also the status change to 0 if they log out, what i need is when the student didn't log开发者_如何转开发 out and Shut down their DS's , the status should be 0,, i don't have an idea to it, any suggestion would be helpful for me ..

FYI ,DS opera browser limitation here

Due to the stateless nature of the web, there is no way to get notified what a user shuts down her browser.

The usual solution to this problem is to have some kind of an "I'm still connected" notification using ajax calls, and a timeout on the server side when a user hasn't checked in after a while.

As far as I can tell, there should be a problem doing that on the DS opera browser.

While itsadok is correct, you could tell who connected recently by using sessions for all your pages. Life would be a lot simpler if you implement your own session handler using a database for storage - and keep (a copy of) the authenticated username in a separate field from the session data.

C.