>If I use txt.lostfocus as a validation event, what is the best or most correct approach
>eg...
>

mytxt.lostfocus
>***************
>if ! passvalidation()  && some validation code
>   this.setfocus()
>   nodefault
>   return .f.
>endif

>
>I'm thinking I don't need nodefault and return .f.

You can remove RETURN .F.