samba - Dec 2005 - SAMBA + PAM module

Hi all

I would like to setup SAMBA 3 with LDAP, on Redhat Enterprise server 4.0 
. So i am configuring PAM, to include pam_unix2.so .
i don't have any file called pam_unix2.so, i have only pam_unix.so. so 
how do i go about it.

Regards
Niranjan