Newbie Forms 4.5, LOV, and displays

Hi,

[Quoted] [Quoted]     I've searched documentation and text books without success to try [Quoted] and do the following simple thing.

        When the form retrieves  data some of the fields might be codes
        e.g.  table orders might have field item codes that refer to

        I simply want to be able to define a non table text item that displays the item description for an existing item code.

        This should change when the user selects a new item code from a LOV.
         The question really is what trigger should be used in such a case.

        I'm sure this is very easy but I just cannot get this right.

        All help gratefully appreciated.

                    Michael.