See http://www.craigberntson.com/Articles/kb006.htm

>I am using into a form:
>
>

>  select mytable
>     go bottom
>        cod = mytable.cod + 1
>    appe blank
>        replace mytable.cod with cod
>

>
> I think this rotine is not suitable because some costumers complain
>that for some reason the code become repetead
>Is there a more eficient way to do it ?
>