Action on leaving a field: I wonder if you can help me with this technical design issue:
In order for a process.txt file to be run, does it have to be off a button or can it be activated on leaving a particular field? (What I want is to scan a value into a field and after the scan the process should start.)

The InputScript cannot be activated on leaving the field. I suggest you program the scanner so that it executes an "Enter" after inserting the field value. You can then start the InputScript with an
"On Enter process=..." command.