I've spent some time reading up on digital signatures and I'm still not sure how to implement, or whether it can do what I'm looking for it to do. We have a form that is completed by a sales person taking an order using Reader. After the form is completed, I used Paul's script on a button click event to change all the form fields to "read-only" and to clean up some formatting. The sales person can then save the form through Reader extensions and can email it to the customer. Whne the form is opened, Paul's script runs again on the doc:ready initialize event to present the form to the customer in the read-only version, which the customer can then print, sign and return to us (the finance folks say we've got have the paper copy -- :-(). Unfortunately we've now had instances where a customer will open the form in Acrobat (not Reader) and edit the text portions of form, and those edits are not easily seen.
What I've like to do is, as part of the button click event, have the some function available, so that, if I understand the digital signature function correctly, if the customer edits the form using Acrobat, some sort of warning is visible on the document so when we receive the printed form back, we know it's been altered.
If I can make the paper version work, I think I can move folks to the next step of e-sig and paperless forms over the Web, but I've got to restore trust in pdf as a secure medium first. I don't want to go back to Word forms (Yuck!) which some folks think are more secure after this incident.
Thanks for everyone's thoughts and help.
If you never need to modify the PDF again, (for example don't need to edit the form after the client pays, etc), would it not be simpler to just print to PDF to create an invoice that could only be printed. You might still need to apply security to the document in acrobat to prevent editing.
Is it possible to post the code for locking fields?