What I want to do Is when I click on a listbox filled with childIDs.
I want the child form if it is open to show the detail Record.
I can get the id from the list.

#Region "Events"
Friend Event ShowDetailRecord(ByVal orderDetail As bsOrderDetail)
#End Region

Private Sub lst_RecordDetail_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles lst_RecordDetail.SelectedIndexChanged
Dim orderDetail As bsOrderDetail = CType(lst_RecordDetail.Items(lst_RecordDetail.SelectedIndex), bsOrderDetail)
RaiseEvent ShowDetailRecord(orderDetail)
End Sub

But how would I pass it off to another form?

frm_Detail doesn't know about frm_Master or should I pass a reference to a child when I create the master form?