no. in the Validate() method of your textbox put something like this:

if Inlist(This.Value, CheckValue1, CheckValue2, ...)
   ReturnValue = .t.
else
   messagebox("You must enter a valid number", 0+16+0, "I've got a problem...")
   ReturnValue = .f.
endif
return(ReturnValue)

>so would it go something like this?
>
>if inlist(.......)
> return
>else
> messagebox(.......)
> validate = .T.
>endif