Is it possible to embed paypal in an IFRAME. I have tried to do this but it just came back a blank page as if there was nothing on it. I dont want to use adaptive payments.
They are probably prohibiting it by setting the X-FRAME-OPTIONS header. It's a security measure and there is no way to work around it.
If you have a payment running through PayPal, you can provide a "back to site" link - that's all you can do.