Public Sub GetData(ByVal InstForm1)
        Dim myDataRelation As DataRelation
        myDataRelation = New DataRelation _
        ("FA", ds.Tables("firma").Columns("kd_id"), _
        ds.Tables("ansprechpartner").Columns("a_k_id"))
        ' Add the relation to the DataSet.
        ds.Relations.Add(myDataRelation)
        masterBindingSource.DataSource = ds
        masterBindingSource.DataMember = "firma"
        detailsBindingSource.DataSource = masterBindingSource
        detailsBindingSource.DataMember = "FA"
        Form1.dgv1.DataSource = masterBindingSource
        Form1.dgv2.DataSource = detailsBindingSource
    End Sub