Trying to get Google Checkout and PayPal to work with a custom .NET site or solution has been a problem for as long as they’ve been around. If you don’t know what you’re doing, it can be a daunting task, and sometimes even if you do know what you’re doing! Well, I am going to take the guesswork out of this chore once and for all, as I have recently discovered the ultimate way to integrate these payment gateways into your website.
In their documentation, PayPal and Google Checkout both mention that you must put their code into your site exactly as they have it, using the HTML forms they way they have structured them. This is not true. There are only a few bits of information that are required, and so long as they are present in an acceptable fashion, your pass-off to these gateways will work smoothly and flawlessly.
1. Get rid of your form tags.
2. Create image buttons for Google Checkout and PayPal
3. Create your hidden inputs to transfer information to PayPal and Google Checkout
4. BONUS: Hook up Google Analytics.