>In form 1 I have a buttom that calls form 2.
>
> If I am in form 2, how can I deactivate form 1 ?

As soon as form 2 becomes activated, form 1 is by definition deactivated -- not the active form. Do you mean release form 1? The simplest way is to issue a THISFORM.RELEASE() right after you issue the DO FORM FORM2 command in your button.