If you haven't already done so, define an auto-entered serial number field in the Prison table. Define a matching numer field in your Clients table.
Link them like this:
Clients::PrisonUnitID = PrisonUnit::PrisonUnitID
Define a value list that lists PrisonUnit::PrsonUnitID in field 1 and PrsonUnit::PrisonName in field 2.
Format the Clients::PrisonUnitID field with this value list.
Delete the address fields you have defined in the clients table.
In layout mode, add the address fields from PrisonUnit to your Clients layout.
Now, when you select a PrsionUnit from the value list in PrionUnitID, the address fields will automatically display the current address info for the selected prsion unit.
The White Paper for FMP Novices is useful
Lynda dot com has Filemaker Videos (portions are free)
Free unlocked templates are useful for examining design
Starting Point -
A free calendar is available to be bolted onto your database
You can search specific Filemaker sites on this Custom Google Search
Looking at FMP business database demos is useful - some are fully useable
The Excelisys Business Tracker V3.0