[Samba] Efficient way to login/logoff users

[Erich at grad.ufsc.br]

Hi there,
I have a network running win9x/2000 machines, connected to 
a samba server with ldap autentication. I wanna know if 
there's way to receive information about login(principally 
logoff) in a fast way.. The WIN machines take a long time to 
send the logoff message (about 2-3min). I was thinking in 
running a program every time the users login and logoff, this 
program could send a logoff message to a server and it must 
run on windows machines..is there a way to run that program?

Waiting answears,
 Erich Silvestre