We are setting up a system to provide free hotspots to small businesses. Our main goal is to also capture some demographic data (age, gender, etc.) on each user before giving them access to the internet. I've looked at a few captive portals but they all seem to only allow you to customize the look of the sign in page, not the fields on the registration form. We need to be able to capture other data and store it in a database or at the very least post that data to a web server during the authentication process. Any help finding a solution would be appreciated. Thanks.