default warehouse and order type based on customer site and Business Unit

Hello Community,
I want to set a default value for warehouse and order type based on the customer site and Business Unit.
The common field between customer sites and the Business Unit is the Account Address Set Code or ID, as shown in the screenshot in Manage Customer.

in manage business units

So, based on the current Business Unit and customer in the Create Order screen, it should retrieve the information related to this Business Unit and customer.
However, the code below returns an error

import oracle.apps.scm.doo.common.extensions.ValidationException;
import oracle.apps.scm.doo.common.extensions.Message;