The test SIM code worked fine.
I am setting up a replacement donate page for a client where the original page used PayPal. They had two types of donations - recurring and one time. The current PayPal page has an text field that collects a donation amount and then sends that info to PayPal.
It looks to me like I have to build the verification hash before serving the page. Because of this I need to set a predefined donation amount before serving the new donation page to the user.
What are my options for having the user enter the amount of the donation on the donate page using SIM?
There are lots of examples in this forum if you search for it. This thread has one.