>If that works for you, that's fine, but I find your example extremely hard to follow its intent.
>
>

>IF (VARTYPE(OLDVAL(FIELD(i))<>VARTYPE(EVALUATE(FIELD(i)))
>  *
>  * To/From .NULL.
>  *
>ELSE
>  *
>  * Type stays the same
>  *
>  IF ISNULL(EVALUATE(FIELD(i))) OR (OLDVAL(EVALUATE(FIELD(i))==EVALUATE(FIELD(i)))
>    *
>    * same values
>    *
>  ELSE
>    *
>    * different values
>    *
>  ENDIF
>ENDIF

>
>All in all, they're really the same thing.

No, your code is not the same as Dmitry's and it doesn't test all conditions.