Tony,

>The problem is that I don't know what the syntax is to get that row. I can't get it right. I tried various syntax code, but keep on getting errors.
>
>Maybe you can give me a clue?

Are you sure you're doing this in the HookParentNavigated method? It didn't seem so from the code you posted. At any rate, I can't give you the exact syntax since I don't have your data structures, but the sample application's OrderDetail business object has similar code in it to retrieve OrderDetail associated with the parent Orders business object:

    Protected Overrides Sub HookParentNavigated(ByVal bizObj As mmBusinessObject, ByVal e As mmBusinessStateChangeEventArgs)
        Me.GetOrderDetail(CType(e.PrimaryKeyValue, Nullable(Of Integer)))
    End Sub

Best Regards,