If you are trying to stop the session from timeing out all the time you can do this rather than increasing the session timeout.
KeepAlive.aspx
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="KeepAlive.aspx.cs" Inherits="Pages.KeepAlive" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<%@ OutputCache Location="None" VaryByParam="None" %>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title>
</head>
<body>
<form id="form1" runat="server">
<div>
KEEP ALIVE
</div>
</form>
</body>
</html>Keep Alive.aspx.cs
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
namespace Pages
{
/// <summary>
/// Page to keep the session alive
/// </summary>
public partial class KeepAlive : System.Web.UI.Page
{
//- EVENTS ------------------------------------------------------------------------------------------------------------------
#region Events
/// <summary>
/// Page Load
/// </summary>
/// <param name="sender">object</param>
/// <param name="e">args</param>
protected void Page_Load(object sender, EventArgs e)
{
try
{
//Add refresh header to refresh the page 60 seconds before session timeout
Response.AddHeader("Refresh", Convert.ToString((Session.Timeout * 60) - 60));
}
catch (Exception)
{
throw;
}
}
#endregion Events
//---------------------------------------------------------------------------------------------------------------------------
}
}Then in your master page create an iFrame that refreshes to keep the session alive
<iframe id="Defib" src="KeepAlive.aspx" frameborder="0" width="0" height="0" runat="server">
</iframe>