ok here is my dilema.
When a user logs in it updates the db and changes the time field and inserts the current time ( unix time stamp )
then every page they visit it updates the time
if that user closes the browser without logging out they are still shown as online because they havent cleared the sessions and updated the db.
what i want to know is .. is there a way i can determine whether a user is still online by checking the time in the db with the current time and if no activity for 30 mins then set them to offline.
im new to using the unix time stamp
any help would be grately appreciated