DECLARE
        l_result             NUMBER;
        l_progress             NUMBER;
        l_errors              PO_API_ERRORS_REC_TYPE;
        l_chg                 PO_CHANGES_REC_TYPE;
        l_shipment_changes          PO_SHIPMENTS_REC_TYPE;
        l_return_status       VARCHAR2(30);

     BEGIN
 


          fnd_global.apps_initialize(user_id => &user_id,-- This function execution is required before launching the approval work flow.
                                     resp_id => &responsibility_id,
                                     resp_appl_id => &resp_application_id);

        
 
--to set org context in a R12 env
       mo_global.set_policy_context ('S', &org_id);

        -- Create an Object for Changes
        -- po_changes_rec_type constructor takes either po_header_id OR po_release_id to construct the object. 
        -- In case of purchase order pass po_release_id as NULL.
 

        
        l_chg := po_changes_rec_type.Create_object(p_po_header_id => <header id>, p_po_release_id => <release id>);

        -- Add a Line Changes to the Change Object
        l_chg.line_changes.add_change(p_po_line_id => <po line id>, p_quantity  => <value>);

        -- Add Shipment Changes to the Change Object
        l_chg.shipment_changes.add_change(p_po_line_location_id => <line location id>, p_quantity  => <value>);

        -- Add Distribution Level Changes
        l_chg.distribution_changes.add_change(p_po_distribution_id => <po distribution id>, p_quantity_ordered  => <value>);


        -- Now call the change api to execute the above changes
        PO_DOCUMENT_UPDATE_GRP.UPDATE_DOCUMENT(p_api_version => 1.0,-- pass this as 1.0
                                               p_init_msg_list => fnd_api.G_TRUE,-- pass this as TRUE
                                               x_return_status => l_return_status,-- returns the result of execution
                                               p_changes => l_chg,-- changes obj. contains all changes intended to be made on document
                                               p_run_submission_checks => fnd_api.G_FALSE,-- set to TRUE if want to perform submission check
                                               p_launch_approvals_flag => fnd_api.G_TRUE,-- set to TRUE if want to launch approval work flow after making the changes
                                               p_buyer_id => NULL,-- buyer id
                                               p_update_source => NULL,    -- name of a source who is calling this API. In case of manual call can be passed as NULL
                                               p_override_date => NULL, 
                                               x_api_errors => l_errors,-- list of errors if any occurred in execution
                                               p_mass_update_releases => NULL);    
                                               
                                                
        IF l_errors IS NOT NULL THEN
        
          FOR i IN 1.. l_errors.message_text.COUNT LOOP
            dbms_output.Put_line(' Error is ' || l_errors.Message_text(i) || ' - name' || l_errors.Message_name(i));
          END LOOP;
        END IF;

        COMMIT;

     EXCEPTION
     
       WHEN OTHERS THEN
          dbms_output.Put_line('error :' || sqlerrm);

     END;