In this article I demonstrate how to build a solution with an automated registration procedure that requires no maintenance on your part and lets the user unlock the solution in minutes. The method doesn't require any plug-ins and uses PayPal as the payment processor. With some work, you can automate other payment processors in a similar manner. The requirements for this solution are: FileMaker Pro 9 or 8.5 (you'll need Web viewer support), a Web site to host the two HTML files, and a PayPal Sandbox account for testing purposes (click on the link to register free.

First, a few words about PayPal as an automated payment platform. One of the most popular payment processors online, it allows payment for services without sharing credit card details with the merchant. The PayPal platform offers many integration options such as product links for placement in e-mails, Web page links, recurring payments, and dynamically generated carts. You'll use the dynamically generated cart as the integration method in this solution. For this example, you'll call PayPal using an HTML form that sends variables to PayPal. The variables describe the payment and include additional instructions to redirect the user to a special page following a successful payment. The solution reads this special page for the activation code and unlocks the solution when the user reaches the successful payment page.

Let's get started

The first step is to create the HTML files on your server that will send the request to PayPal. Subscribers can download the product1_purchase.html file that provides a starting structure for the PayPal request. Open a copy of this file in your favorite text editor -- BBEdit or Notepad work well. The HTML file includes two sections: a JavaScript function to submit a form automatically (this function is called when the page finishes loading), and a form for PayPal information. You'll make a few simple changes to configure this page for your product.

First, customize the setting for the receiver of the payment. Find the hidden HTML input "business" and change "sales@yourdomain.com" to the PayPal address you use. Next, you want to produce a PayPal receipt. Find item_name and change "my product" to the name of your product, then find "amount" and change the 29.99 price to the price of your product. Make sure to use proper decimal notation and do not omit the period even if you've rounded the price to the dollar (e.g., use 10.00 for $10). Finally, set the special return page with the activation code as the page to go to after a successful transaction. Find "return" and change its value from http://yourdomain.com/product1_paid.html to the complete address of your successful payment page.

This simple HTML form sends information about your business to PayPal, a reference to the product, and a return page the user will be sent to when the payment is completed. Notice the form action sends the user to www.sandbox.paypal.com. When preparing this solution for a production environment, change this address to www.paypal.com to process real payments.