No. That's not how PayPal works. What you want is to either use Authorize.Net (which is a bit of a pain in the butt to get up and running) or FastSpring.
Is there a way to do a PayPal payment without using the html <form/> code in your payment.php example?
I'm concerned about revealing certain things in the html source for my page, such as my paypal e-mail address, which has started to get a lot of spam. Also I'm not enthusiastic about showing the location of the paychecker.php file, or the return URL for after my purchase.
I'm not a php expert, but is it possible to do this strictly through php without any client-side html?
No. That's not how PayPal works. What you want is to either use Authorize.Net (which is a bit of a pain in the butt to get up and running) or FastSpring.