WIP Job completion auto populate remaining quantity to complete in MWA

In R12.1.3 -> Oracle discrete Manufacturing :

Navigation : in MWA/MSCA-> Manufacturing->Assy & Material Txn->Complete Assy>Move and Complete

When we put  a job number and hit enter, system auto suggesting the remaining quantity in quantity completion field. Wip Jobs are opened for 1000s quantity for the entire month and completed batch wise.

Risk: Forklift users who scans quantity have to either clear the remaining quantity in the scan gun@ and scans the required quantity or by mistake they complete the full remaining quantity that system suggesting.

Ask:  How can we make quantity field blank and let user manually put the completion quantity.