If u r having a masterpage then this will be very effective to do the task....
u can have a timer control in page
<asp:Timer ID="Timer1" runat="server" Interval="15000">
</asp:Timer>
and later u can trigger a section of a page with this timer
<asp:UpdatePanel ID="UpdatePanel6" runat="server" UpdateMode="Always">
<ContentTemplate>
<b>U can put ur method over here to do the work.................</b>
</ContentTemplate>
<Triggers>
<asp:AsyncPostBackTrigger ControlID="Timer1" EventName="Tick" />
</Triggers>
</asp:UpdatePanel>