Hi Janek,
I am talking about locking GUI interface. You could call it somewhat different if you like, e.g. "restricted GUI mode" or whatever. Off course, DB would be still unlocked. Also I would say that writing code under assumption that you user is, ehm, mentally challenged might not be a best idea.
Your solution of unlocking database on browser's request would not be useful for me. In fact, one could argue that if this happening often enough it could be more harmful then keeping database open (password strength would be low and simple eavesdropping would be sufficient).
Anyway, thank you for your answer.
Kind regards,
Alexey Popov