Marco,

Just to add a little more to what I wrote...

If you wanted to write a specialised currency control based on EditEnh
(and so allow the user to define their own masks and currency
requirements), you could create a derivation with a dropdown
calculator as you suggested and let the existing mask capabilities
handle the user interaction problems.

If you want to do this, download the EnhComponents and take a look at
the CustomComboEnh unit. This defines a combo-box styled control
based on EditEnh (see also the CustomDateTimeEnh and IBC_LookupEnh
units for different derivations from the CustomCombo).

This may save you some time and trouble. In addition, anything
derived from the EditEnh based can be dropped onto TIB_Grid.

If you build the dropdown from the CustomCombo of the enhcomponents,
you will know that the dropdown will work acceptably over the grid.
The CustomDateTimeEnh would probably be a good example to work from,
it demonstrates how you can share a single dropdown instance amongst
ALL instances of the edit control - saving resources.

I strongly suggest that you build a non-IBO version first, and then
create an IBO-aware version using the various examples available (such
as the EnhComponents themselves). This allows you to more easily
isolate where problems are introduced.

Geoff Worboys
Telesis Computing