Michael,
>Has anyone made use of this Textbox property. Can you preload the autocomplete table so that the suggestions will only include valid Client numbers for instance? I've tried what seems obvious to me but with no success.
Yes, you can preload an autocomplete table with certain values (notice I said "an" instead of "the"). You are not limited to just the one default autocomplete table, but can point one or more controls to your own speific autocomplete tables (set the Textbox.AutoCompTable property), which can reside anywhere (they must have all of the required fields, although they can have additional fields, too).
Note, however, that even with pre-loaded values, your users can add to and even delete from the list. The only way I have found to prevent that is to mark the table as READONLY at the OS level, which does work nicely to protect your list.
Read the help again on autocomplete and ask away if you still have problems figuring it out. You also might pick up a clue or two from the AutoComplete explanation (Item #1) in the VFP9 lead article in the FoxTalk 2.0 sample issue, available here:
http://www.foxtalknewsletter.com/Media/MediaManager/nFTsample.pdf