The reason the text boxes are disabled, is because there is no record in the ControlSource view. You can either manually call the New() method of the associated business object, or (as you mentioned) make one business object a child of the other, and set the child's lNewChildOnNewParent property to True.
Regards,
Kevin McNeish Eight-Time .NET MVP VFP and iOS Author, Speaker & Trainer Oak Leaf Enterprises, Inc. Chief Architect, MM Framework http://www.oakleafsd.com