Access and SQL Server programmer learning FileMaker.

I've got a multi-table database working pretty nicely. Here's my
dilemma. How do I develop an interface that will allow users to find
records and enter data where they need to, but prevent them from
screwing up the relational structure by entering dependent data under
the wrong record? In other words I'm concerned if I leave the status
area available, a user can possibly navigate to a layout for a
dependent table and enter data which is not keyed properly to the
master table. But I'm finding it challenging to provide buttons to
allow the flexibility the users will need.

Are there any good example databases for this problem? Or is this
something that doesn't seem to happen in actual use?

Thanks,

Paul Norris
UCSF

Check out the "FileMaker Business Tracker" at www.excelisys.com
that should give you a good idea of what is possible and how coding
usually works in FM.