I need a special script implemented. Basically, I sell a item on clickbank, I have a thankyou page that has a download link so that after purchase, they receive a download link. The problem is that anyone who visits the thank you page url from anywhere gets access to the product for free. We must prevent this. I need a script that will only load the thank you page after checkout from clickbank only. Anyone who visits the url from google search or anywhere lese must be blocked! Only checkout from clickbank it must load.