API to Cancel all PO Lines when closing the PO but Header status to be CLOSED

Hi ,

We have a requirement and need your guidance to know on the feasibility

1) First we wanted a way where in when we close the PO , we wanted all the lines to be in cancelled status but the header status must be closed.

2) If suppose there were 10 qty ordered each price of 10$ and out of 10 5 were already received and you wanted to close the PO , then I wanted all lines to be cancelled and header status to be closed and the amount should show the balance.

Please suggest.

Uday