API to get on hand and available to reserve quantities in Oracle Apps

DECLARE
   x_return_status         VARCHAR2 (50);
   x_msg_count             VARCHAR2 (50);
   x_msg_data              VARCHAR2 (50);
   v_inv_item_id           NUMBER;
   v_org_id                NUMBER;
   v_qty_on_hand           NUMBER;
   v_res_qty_on_hand       NUMBER;
   v_atreserve             NUMBER;
   v_attransact            NUMBER;
   v_qty_reserve           NUMBER;
   v_qty_sugstd            NUMBER;
   v_lot_control_code      BOOLEAN;
   v_serial_control_code   BOOLEAN;
BEGIN
   -- Set the variable values
   v_inv_item_id := :item_id;
   v_org_id := :org_id;
   v_qty_on_hand := NULL;
   v_res_qty_on_hand := NULL;
   v_atreserve := NULL;
   v_lot_control_code := FALSE;
   v_serial_control_code := FALSE;

   -- org context
   fnd_client_info.set_org_context (1);

   -- Calling API
   inv_quantity_tree_pub.query_quantities (
      p_api_version_number    => 1.0,
      p_init_msg_lst          => 'F',
      x_return_status         => x_return_status,
      x_msg_count             => x_msg_count,
      x_msg_data              => x_msg_data,
      p_organization_id       => v_org_id,
      p_inventory_item_id     => v_inv_item_id,
      p_tree_mode             => apps.inv_quantity_tree_pub.g_transaction_mode,
      p_is_revision_control   => FALSE,
      p_is_lot_control        => v_lot_control_code,
      p_is_serial_control     => v_serial_control_code,
      p_revision              => NULL,
      p_lot_number            => NULL,
      p_lot_expiration_date   => SYSDATE,
      p_subinventory_code     => NULL,
      p_locator_id            => NULL,
      p_onhand_source         => 3,
      x_qoh                   => v_qty_on_hand,
      x_rqoh                  => v_res_qty_on_hand,
      x_qr                    => v_qty_reserve,
      x_qs                    => v_qty_sugstd,
      x_att                   => v_attransact,
      x_atr                   => v_atreserve);
   COMMIT;
   DBMS_OUTPUT.put_line ('On-Hand Quantity: ' || v_qty_on_hand);
   DBMS_OUTPUT.put_line ('Quantity Reserved: ' || v_qty_reserve);
   DBMS_OUTPUT.put_line ('Quantity Suggested: ' || v_qty_sugstd);
   DBMS_OUTPUT.put_line ('Available to Transact: ' || v_attransact);
   DBMS_OUTPUT.put_line ('Available to Reserve: ' || v_atreserve);
EXCEPTION
   WHEN OTHERS
   THEN
      DBMS_OUTPUT.put_line ('ERROR: ' || SQLERRM);
END;