How to update the Customer field value of PO Item under the Delivery Address Tab?

Hi Friends,

     i tried to update the Customer field Using Bapi_PO_change.I passed the PO Order no,POADDRDELIVERY data with Item no,Adrees no,Customer no.But i am getting no data changed message from return table.I attached the screen shots.So please suggest me the helpful information for resoving this issue.

Thanks,

Dinesh