Simple Timer Control Example

<asp:ScriptManager ID="scriptManager" runat="server">
                        </asp:ScriptManager>
                        <asp:UpdatePanel ID="updatePanel" runat="server">
                            <ContentTemplate>
                                <asp:Image ID="image" ImageUrl="Images/1.jpg" runat="server" />
                                <asp:Timer ID="timerControl" runat="server" OnTick="timerControl_Tick" Interval="2000">
                                </asp:Timer>
                            </ContentTemplate>
                        </asp:UpdatePanel>

protected void timerControl_Tick(object sender, EventArgs e)
    {
        //string path = Server.MapPath("~/");
        string imageURL = image.ImageUrl;

        if (image.ImageUrl == "Images/1.jpg")
            image.ImageUrl = "Images/4.jpg";
        else if (image.ImageUrl == "Images/4.jpg")
            image.ImageUrl = "Images/1.jpg";
    }