InfoPath Dev

Hi guys, I'm a graphic designer, new to InfoPath and getting a problem. Hope you can help! I'm adapting a Travel Form which needs to be signed by the APPLICANT, then sent to their LINE MANAGER, signed by them, then sent to a TRAVEL OFFICE. The TRAVEL OFFICE need to receive an editable form so that they can change any details they wish. They are not in our building or on our IT network, where the Publsihed form will sit. Currently I have 2 Submit buttons, both using Rules. 1st one submits to an email address of the LINE MANAGER which is filled out by the APPLICANT and appears as a field on the form. The 2nd Submit button sends the form to the TRAVEL OFFICE which appears in a Read Only text box as a field on the form. The problem I am getting is that the form is not editable by the LINE MANAGER even after the APPLICANT has signed and pressed Submit! I have tried un-checking the "When signed, make controls read-only" box in the '"Section Properties" window but it doesn't seem to work... Do digital signatures just make everything un-editable? Is that their purpose? My boss wants to have them but also wants to keep the form editable after 2 (even 3) signatures.. Is this possible? (Please reply as simply as possible or I just won't get it) (using InfoPath 2010 on Windows 7 64-bit) (also have access to 2003 and form was originally built in 2003)

Hi, unfortunatly the response is "no", a signature make the part of a form read only because the person who have sign it validate this part on his current version, if someone can modify it his signature is just make the signature invalid.

So can I choose a section and make the signature apply to just that section and lock everything within that section, but keep everything else editable?