If you have a Hylafax print driver, then all you need to do is use that. Now I thought we could make a Fax button on an Acrobat form and use the action for this being to submit the whole PDF to the Hylafax server... but the trouble is, Acrobat does not send any other data .. such as the field data so Hylafax does not know what to do with the PDF. Another possibility is to use the PWP to do the faxing. Once you have submitted the form, you then get an option to fax the PDF onto someone else. The script then merges the XFDF data with the original PDF ie. flattens it, and then sends it to the Hylafax server ...
