In the application I am developing I have to store the time some particular users remain logged into the application, unfortunately, in web applications there are several ways the user can log off.
1.- User clicks log off. 2.- User session expires. 3.- User closes the window. 4.- User types another site url in the address bar.
The first one is quite easy because the application gets control of the logging off process. But in the other ones it gets tricky.
What would you do to solve this problem?