I've tried everything I read here and there.

1. putting the setcookie time in the Your_Account index.php page at 0.
2. putting all the setcookie time in the includes/session.php page at 0.
3. putting the setcookie tin in the admin.php page at 0.

Still when I close my browser and I reopen it, I'm still logged in !!!
Getting really pissed here ! :x

Not sure what your at, but your browser has its own stored cookies, delete all those before you try again.