FTP PAM stack configuration question

[Adrian Pillai_1]

Hi All,
I'm trying to stack 2 pam modules for ftp authentication. I'm doing this on both HP 11.0 and 11.11.
This is in /etc/pam.conf:
ftp auth required /usr/lib/security/libpam_ntlm.1
ftp auth required /usr/lib/security/libpam_unix.1

However, ftp doesn't seem to prompt for a 2nd time for a password. How do I enter 2 separate passwords at the single password prompt? or is there some other way that I can require users to use more than 1 factor of authentication for ftp?
thanks in advance...