Ad show in time interval using timer and adrotator

<asp:ScriptManager ID="ScriptManager1" runat="server">

</asp:ScriptManager>

<asp:UpdatePanel ID="UpdatePanel1" runat="server">

<ContentTemplate>

<asp:AdRotator ID=ad runat=server AdvertisementFile="~/adsbanner.xml" />

<asp:Timer ID=tm Interval=3000 runat="server">

</asp:Timer>

</ContentTemplate> 

</asp:UpdatePanel>