Redirect after a wait in update panel

I have a timer . I need to redirect to another page when the time ends. but before redirecting I have to show a message that Time has ended. I have put the timer within a update panel.But the desired wrok is not done because of update panel. I am giving the detailed design and code below.
Desgn:
<asp:PlaceHolder ID="phtimer" runat="server">
                    <asp:UpdatePanel runat="server" ID="upDuration" UpdateMode="Conditional">
                        <ContentTemplate>
                            <asp:Timer ID="timerDuration" runat="server" Interval="1000" OnTick="timerDuration_Tick">< ...