Use
ON ACTION blocks to execute a sequence of
instructions when the user raises a specific action. This is the
preferred solution compared to
ON KEY blocks,
because
ON ACTION blocks use abstract names to
control user interaction.
ON ACTION zoom
CALL zoom_customers() RETURNING st, cust_id, cust_name
Add the
INFIELD field-spec option to make
the runtime system enable/disable the action automatically when
the focus enters/leaves the specified field:
ON ACTION zoom INFIELD customer_city
LET rec.customer_city = zoom_city()