microsoft access - Link new record to existing form

In Access 2007. We enter a new record on a form. Then we click a button which has a macro action to open another form. What can I do to make the new form open but linked to the new record? I understand that I need the primary key on the new form etc. If the record was saved I can make the second form open with that data. But My Question is when it's still a new record/form we need to navigate directly onto the linked form...

Please share some direction on this..