I am currently using Paypal, and this is what I have for paypal:
http://i.imgur.com/OtwQP.jpg

It's a small popup. This allow's the user to enter the re-ocurring and the amount then click donate and it takes them to paypal and let's paypal do the rest. Paypal grabs those two variables from me in a post.

How in the world do I do that same thing with this system? Documentation is very complicated and confusing.