Naomi Nosonovsky
I've become a big fun of Cursor Adapter lately, so I would probably use Cursor Adapter here as well.
Anyway, let's try to work out textbox and SET KEY idea.
In the textbox interactive change try:
lcKey = alltrim(this.value)
** Assuming the table is ordered by Customer and it is the current alias
SET KEY TO m.lcKey && This should filter all records matching the entered value
************************************************************************************************************************
If this would not exactly work as you want, you may construct lcKeyMin, lcKeyMax and use the second version of SET KEY command. Check details in the help.
Let me know, if you would be able to make this idea work.
Other ideas would be using local parameterized view.