The source code to implement OrderForm in web pages has become too complex and is impractical for most end users to implement. It is no longer recommended or supported by AShop.
The Order-Link method is easier to use. Order-Link source code is automatically generated for each product and it can be used in remote (outside of the AShop installation) web sites.
For those who wish to continue using OrderForm code in web pages, the OrderForm code can be copied from the source code of the pages that are generated by the catalogue.php script. The head code must also be copied and included in OrderForm pages. Not all of the functions and parameters are necessary, but the ones that are used must be included in the head and also in the buy button form actions. If you understand enough about the functions and parameters to tackle this type of setup, more power to you and good luck. We prefer to support and continue improving the Order-Link method now because it is way easier to use and can be used in more places.