How to identify who are online?

[eluser]chengfeng[/eluser]
Hi everyone! I have a web application to allow my employees to log-in. When they log-in, I store the session id and date time into the database. when they click log-out, i update the table with the log-out date time.
My problem is if they not click the log-out link by close the browser. So, it not update the table.
What I want to know is : Even, they close the browser and the session is time out, it will update the table with the log-out date and time. How can I do?
This case, I just want to know how are using the system. Or anyone know other way to solve this case.

Thankfully!

[eluser]InsiteFX[/eluser]
You could use a cookie.

When user login, create a cookie with there information for your table.
Make sure the cookie last for a week or so.

Now when the user logs back into your system you can check for the cookie
update your table, then delete and recreate a new cookie with the new
information.

I am sure there is a better way.

InsiteFX

[eluser]wahyu24[/eluser]
i have same problem
please help me...