recurring payment to already running paypal script

Question

I have seen many related questions but didn't find any answer.

I have successfully implemented transactions through paypal but now I am asked to implement recurring payments through paypal. I have searched but couldn't find any material that can help me how to implement this.

First what I have implemented. I ask user to select amount. User selects amount, I transfer user to paypal where he enters his information and do transaction. After successful transaction I show user the transaction id and stores ipn information and user information in my database.

Now I want to give an option to user to select recurring payment with yes or no. If user selects recurring payment then his recurring payment will be done with the amount that he selects above.

Now I want to know:

1. What to change in my already running paypal script to have recurring paypal payments?
2. recurring details will be asked at time of payment.
3. What additional parameters to be sent now to have this?
4. How to test it on already running application?
5. What parameters paypal will send back to me as ipn?
6. I have tried to understand from paypal website but couldn't.

Answer 1

In this list there are all the Docs you need. theese are not casual links taken from the net, theese are a set of links i have collected when i had to do exactly the same thing you are trying to do now. ;)

• Handling Recurring Payments (Official)
• Subscriptions and Recurring Payments Variables ^{( 3 )}
• Advanced Techniques - \"Subscribe\" Button HTML Code ^{( 1 )}
• PDN - Subscriptions Overview
• Adding PayPal Checkout to Your 3rd-party Shopping Cart
• HTML Variables for Website Payments Standard ^{( 3 )}
• Canceling Individual Subscriptions ^{( 2 )}
• IPN and PDT Variables ^{( 3 )}
• Instant Payment Notification (IPN) simulator ^{( 4 )}
• IPN Testing ^{( 4 )}
• Payment status – what does it mean? ^{( 5 )}
• Sample Code

happy coding. ;)