CREATING CGI SCRIPT FOR PROTECTING CLICKBANK EBOOK THANK YOU PAGE

I want the url of my ebook download page to be accessible only after going through the Clickbank payment system successfully. Currently someone can just type in the url of my download page(thank you page) and download without paying. Clickbank recommends doing this to protect it [login to view URL] I also want good looking picture banners to be placed on my affiliates page. Then an email form should be created on my support page so that instead of showing my email address the customer can just enter the subject and body of the message and click send. I am sure my hosting serice supports that. That is all, I already have a website up and running but I need these additions.