>>Try setting the value of the textbox to 0 (zero) or any number.
>
>Thanks.
>
>Well, that would be what I call an "unbounded" TextBox (, and perhaps I'll end up doing precisely that). By "unbounded" I mean that it doesn't have a ControlSource.
>
>The point is that the data is eventually stored in a character field, so I wanted to use the .ControlSource correspondingly; but that doesn't seem to work correctly.
>
>> ... And I would set the input mask to "999.99" (not #s).
>
>Actually, now I see that I have been doing exactly that; but it doesn't work, probably because the value of the .ControlSource isn't numeric.

Unbind the control in Gotfocus, and bind it back in lostfocus. Something like this, not tested:

*GotFocus
This.addproperty('cSource',this.controlsource)
This.addproperty('cOldValue',this.value)
This.controlsource=''
This.inputmask='999.99' && Maybe not necessary
This.value=val(this.cOldValue)

*LostFocus
Replace (this.cSource) with str(this.value,6,2)
This.controlsource=this.cSource
This.inputmask='' && Maybe not necessary

Adding the cOldValue property makes it easy to Escape back to the old value in KeyPress