> I have two combo boxes in a grid, all of which support incremental search.
> One that has a list of category codes and the other detailed codes derived > from an extention of the category codes.

i wonder if you even want to display (in combo2) items that are not
related to the selection made in combo1. typically, in the valid
event of combo1 i would filter the rowsource for combo2. depending
on how many items in the combo2 list, this may be helpful to the
user if you reduce the number of item they have to look through.