Working With authorize.net Server Integration Method (SIM) Payment Gateway, Part 2: Proper Form Design
Example 1: Simple Order Form

Select a membership level: 

Your membership comes with a free T-shirt. Please select a size: 

Please check the email lists you'd like to join (you can unsubscribe at any time).

Would you like to make an additional donation?

Click the "Order Summary" button below to confirm your order and proceed to the payment screen.

Order Summary

Order details will appear in this space once you click the Order Summary button.

Working With authorize.net Server Integration Method (SIM) Payment Gateway, Part 2: Proper Form Design