[gdm-list] Execute script on failed login

[Sascha Ochsenknecht <s ochsenknecht web de>]

Hello,

I found out that there are various scripts/commands which can be defined 
to be executed on login (PreSession, PostLogin ...). I would like to do 
something similar when login fails.
E.g. a script which sends an email when somebody tries to login with a 
wrong username or password.
Any ideas/suggestions how I can do this?
(A thing like /etc/gdm/FailedLogin would be great :-) )

Important for me is that the script is triggered immediately when the 
(failed) login happens (so, cron job which grep's the log files isn't an 
option).

Thanks in advance
Sascha