Create some new tables (not databases :smileywink: ) for your database.
Table 1, Documents:
Document ID and other fields
Table 2, People:
PersonnelID, Name, etc.
Table 3, Signatures
DocumentID (to match with Documents table)
PersonnelID (to match with People)
Type (signer or witness)
You'll need to create relationships that link these three tables and layouts that use these layouts to display the data you need to do what you want.
Speakerbruce, I could be wrong but it sounds like creating a database is a new thing for you. If so, I suggest you prepare to spend some time reading up on databases, completing a tutorial or otherwise educating yourself on how to design databases and specifically how to do it with Filemaker Pro.
We'll help you all we can, but some basic study on your part can greatly speed up the process for you.