Partial Class _Default
    Inherits System.Web.UI.Page

    Protected Sub Menu1_MenuItemClick(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.MenuEventArgs) Handles Menu1.MenuItemClick
        Select Case e.Item.Value
            Case 0
                Me.Menu2.Items.Add(New MenuItem("New Menu Item 1"))
            Case 1
                Me.Menu2.Items.Add(New MenuItem("New Menu Item 2"))
            Case 2
                Me.Menu2.Items.RemoveAt(Me.Menu2.Items.Count - 1)
                Me.Menu2.Items.RemoveAt(Me.Menu2.Items.Count - 1)
        End Select
    End Sub
End Class