Thanks and cool program.
I was reading about. and Maybe this can do what i need!

Iam a ISP and beside my NAS users autentication ( They have the IP
assigned to in this autentication by my PR4000 NAS), Iam looking for a
captive portal to.
Purpose:
Iam to put messags that concern this user, about payment, billing this
things.
User log in but cant not use internet, nothing, but they are redirect for
this captive portal. at this place. he need to put username and password
again to gain acess on internet or not!!

It´s possible to do that with this probram?
If this is possible How i do that? was little confuse this side of
configuration to me:
Iam using a PR400 from cyclades and ICRADIUS to log..
Any help can be cool!!
Thanks.