Thanks for that advice...I'll try it all out some time today.

It was VFP 7. It's a bit frustrating at the moment because I've spent most of my working career using VB and Delphi, which do things very very differently.

I found a work round in the end, by setting BoundTo to false and setting the display value programmatically, but even then I had problems with using a private variable. I landed up creating a property.