You assign the FK to the details with the PK you just generated in your code. Same way as for the assignment of the PK.

How do you pass informations between your layers? With the dataset? If it's the case, then you don't need extra public properties in your BL, the PK and FK are accessible in the dataset.

>BTW, how should I reference this PK when I add records to the details? Should I save both ID and PK in public properties of the BL?