BufferChanged Event
The BufferChanged event is triggered whenever the user does anything—including Cut and Paste—to change the contents of an EntryField.
This event has the following syntax:
on BufferChanged [entryfieldname]
entryfieldname is optional if you specify this event in a field script.
The following attributes of the FrameExec class can be used in the BufferChanged event block:
TriggerField
Specifies the EntryField that has changed
OriginatorField
Specifies the field in the on BufferChanged statement
More information: