Jeff-p
I have had limited use with the FMP9 php site developer. If you are trying to build a complete site using php, I recommend the FMStudio plug in for dreamweaver.
What I do know is that you need to indicate the action of the button on the edit form so it can perform the edit function in the filemaker php folder. You must also carry the record id as a hidden field on the page, within the form, of your edit page. This tells filemaker which record to edit. Your response page must be told to edit the record and you must have all fields which are on the edit form listed as fields to be edited.
Without looking at the whole page code, it would be very difficult to see what is going on. Hope this helps!