I need FaceBook API

This is for FaceBook Developers, what I want should be a simple. I need an API that would enable me make a post on FaceBook and then send an email through an autoresponder to all those that share the post. It should work like this: The API will be attached to an image post I shall make, such that after an FB user shares the post, an input box will appear asking for the users' email address to receive a free gift. And as soon as the user enters the email address, my autoresponder will send an email containing the free gift to the FB user. I need this completed within few days, you should already have similar codes you can easily modify for me. Looking forward to doing this with less than $100. I will pay through Safepay or Escrow if available or through Paypal.