How update Fund Center and Commitment Item after GR completed in PO?

Hi friends,

                Funds management was activated during the year and hence there are Some PO's now doing the process it will show errors like fund center or commitment item missing. In PO i check Commitment items And Fun center  tab in DISPLAY mode.how to those fields change into enable mode.

             PO process is  PO->GR-> Invoice

     Only PO is completed 2 fields in change mode but GR also completed 2 fields in Display mode.. I want to change 2 fields in PO after completion of GR Po's.  Please help me ..it's urgent requiremnet..