Regarding pppd with pam authentication and pptpd

I am currently working on a vpn server, and I use pptpd with pppd and
trying to get pam working. I want to setup pam authentication because
I want to limit simulatenous logins per user to 1.
[root box pam.d]# pptpd --version
Poptop v1.2.1
pppd version 2.4.3

/etc/pam.d/ppp contains:

#%PAM-1.0
#auth       required    pam_login.so
auth       required     pam_stack.so service=3Dsystem-auth
account    required     pam_stack.so service=3Dsystem-auth
session    required     pam_stack.so service=3Dsystem-auth
#auth    required  pam_permit.so
#auth    required  pam_warn.so
 --- #comments for testing purposes

/etc/pptpd.conf contains:
option /etc/ppp/options.pptpd
logwtmp
localip 192.168.222.1
remoteip 192.168.222.2-250

/etc/ppp/options.pptpd contains:
[root rickp4a pam.d]# cat /etc/ppp/options.pptpd
name pptpd
refuse-pap
refuse-chap
refuse-mschap
require-mschap-v2
require-mppe-128
proxyarp
lock
nobsdcomp=20
ms-dns 202.67.240.221
ms-dns 202.67.240.222
debug

Any idea on how to set this up? I know I add users with adduser ...
but I don't know what I have wrong. Trying to setup this vpn server
for windows clients. And if I use adduser, does the person need a home
directory? Since it will only be for pppd and pptpd ... they won't
ever be logging in any other way.


Thanks,
Bob