[ZPT] zope and mutual exclusion reserved area

[mafa77]

Hi!
I'm building a site with a particular administration area: I manage
login with MySQL and sessions and I want exclusive access to reserved
area, to do so I use a flag in db that indicates if an admin is in
reserved area. The problem is that if admin close browser without log
out, flag doesn't change and admin can't login never in thee future
because of "an administrator is in the reserved area". I try to use
expiration time of session with negative results. 

Only if I use a javascript and window closing can I resolve it?

Exist a product that can help me?


Thanks in advance,
Fabio Marcone