I am implementing amazon inline checkout API in my Oscommerce store. Am following these steps given in the PDF http://amazonpayments.s3.amazonaws.com/documents/Inline_Checkout_Implementation_Guide_US.pdf I am struck up in creating signature & ISO 8601 timestamp. I couldn't find any brief documentation regarding this issue. Kindly explain about these steps in detail. And also is there a possibility to implement both inline checkout and fulfillment checkout in the same store??