212973 Butterfly Marketing Code Addon

I own the Butterfly Marketing script and need it to do the following: 1.) When a prospect lands on the default squeeze page, they are required to enter an Invitation Code along with their Name and Email address in a web form. The ID code entered will actually be the ID Number of the Affiliate who referred the visitor to the site. (Affiliate ID numbers are generated within the BFM script.) No Invitation Code = No Access! If you know how to work within or around the Butterfly Marketing Script... please respond. I understand there my be details i left out, but want to make sure we are on the same page first and you can do what I need taken care of. There's some other database work I will like to get done later on down the road. So there will be other jobs and I'm looking to work with someone who can complete projects on time.