HP 3000 Manuals

HP ALLBASE/4GL Developer Self-Paced Training Guide

Lesson 24 - Extending the Application Logic 

In this lesson you will alter the product_proc process and the screen
field logic function product_key_read.  You will also create several new
logic blocks, including the option_key_read function, which is called as
an after function on the option_no field on the option window.

MPE/iX 5.0 Documentation