Paypal subscribe now button

Question

Hi,

I have built an information portal in PHP [Something like a recipe book], where the first few recipes are free to access. The advanced recipes are available only to paid members.

I intend to use a simple subscribe now paypal button. When the user clicks on this button, he is directed to paypal website and upon payment redirected to my site.

How do I collect the payment information from paypal? I do not want to use a wsdl.

I need the information to update my user level field [0 for registered users, 1 for paid users] in the users table.

Any pointers? Does IPN do the trick for this? Is there a better solution for this?

Thanks, Bharadwaj