In Capacity Journal, Can Item No. be blank?

SIMON.0211

I read the Help of Capacity Journal, (NAV 4.0) "Capacity Journal Window, Related Topics", said, "you post consumed capacities that are not assigned to the production order.". I tried but fail, the message said "You must specify Item No...".
How should I do if I need to adjust capacity without prod. order? ](*,)

cernst

Capacity journal is for consuming time on prod.order so you need to specify an item no. What is it you want to do?

SIMON.0211

I need to modify the capacity cost spend on a work center(for a prod. order), but the prod. order is finished.