Tyler,

>its of type numeric

try this in the GotFocus:

IF EMPTY (THIS.Value)
  KEYBOARD '403' PLAIN CLEAR
ENDIF

I currently can't think of another way to accomplish this, since I don't think that you can assign only the left portion of a number to a Value property ... But if I were you, I'd rather use a character field to store phone numbers.

HTH,
Armin