Firebird record and field locking

Hi,
I'm quite new to Firebird/Interbase, coming from M$ SQL and MySQL background.

My questions are:

1. How Firebird deals with record and field locking?
Could someone provide code samples of setting a lock and checking if record or field is locked?

2. I understand that lock is unset on commit or rollback.
What happens if an application that set a lock crashes, therefore doesn't perform commit neither rollback?

Thanks
Peter

Please read these documents:
http://www.ibphoenix.com/main.nfs?a=ibphoenix&l=;PAGES;NAME='ibp_lock_records'
http://www.ibphoenix.com/main.nfs?a=ibphoenix&l=;PAGES;NAME='ibp_waterloo'

Then come here and ask questions

--
Best regards,
Fikret Hasovic http://fikret.fbtalk.net
TAMP R&D Team
FirebirdSQL Foundation member.
- Join today at http://www.firebirdsql.org/ff/foundation
JEDI VCS contributor
http://jedivcs.sourceforge.net/

Fikret,
Thanx for the links, had a good read of them and other IB/FB related docs.
Two questions:
1. I understand that IB will automatically rollback a transaction if client application will end before ending the transaction. Does it apply to FB as well?
2. Accoring to Interbase documentation if a program ends without closing the database, data loss or curruption is possible. Is it a case with FB as well?
The problem I see with the application I'm currently developing is that lots of clients connects to db via Internet (VPNs over broadband or dial-up). I'm' afraid what may happen if Internet connection is dropped.
Could you explain what kind/level of corruption are we talking about?

Cheers,
Peter