samba - Aug 2005 - find membership in group for users

Hi,

my question is perhaps out of the list subject sorry.

I have samba with LDAP backend, my goal is to write an interface in PHP 
to manage adding/deletings users in groups.

But first of all : how does i do to show all the  users in  group 
'group1' using  ldapsearch ?

And the other way round : how can i find for one user in which groups he 
is ? (still using ldapsearch)

Thanks for any help or tips