Private Sub Button8_Click(ByVal sender As System.Object, ByVal e As _
  System.EventArgs) Handles Button8.Click
 
        If detailsForm Is Nothing Then
            detailsForm = New Form3  <------ da befindet sich das DataGrid1
            detailsForm.BindingContext = Me.BindingContext
            detailsForm.Show()
        Else
            detailsForm.Activate()
        End If
 
    End Sub
 
End Class