Making Pay Per View work on my website

I have set up a sample pay per view content on this page. http://www.tinyflix.paretoid.com/flight-of-the-eagle/

The Module 05 - Structure file should be available only to those who pay $5 via PayPal. But at the moment the PayPal buttons are not visible and the file is available from a direct link!

Can you help set it up properly? Thanks.