When Setting up Set Field, there are two Specify buttons that must be clicked. To get Set Field [Table::Field ; Expression], add set field to your script and click the first button (specify target field). Select Table::Field from the list of fields. Do not click the specify button next to the repetition box. Click OK to close this dialog box. Now click the lower specify button (calculated result) and create the expression to the right of the semicolon (;). Do not try to type in the semicolon.
How do I solve for these - If [Not Get ( FoundCount ) // no records were found ]
Show Custom Dialog ["No records were found by this search."]
When I put that in, I get an error message or need a & or a ()
Those are script steps, not a calculation to be entered into the specify calculation dialog.
You add them to your script in the script editor by double clicking the step with the same name from the list on the left.
The If and show custom dialog steps then have to be opened so that you can specify the expressions inside the [ brackets ].