SessionID Validation?

Step 1:


 protected void Page_Load(object sender, EventArgs e)
    {


if (!IsPostBack )
        {          
            #region for session validation
            Guid guid = Guid.NewGuid();
            if (HttpContext.Current != null)
            {
                if (HttpContext.Current.Request.Cookies["ASP.NET_SessionId"] != null)
                {
                    HttpCookie cookie = HttpContext.Current.Request.Cookies["ASP.NET_SessionId"];
                    cookie.Value = guid.ToString();
                    HttpContext.Current.Request.Cookies["ASP.NET_SessionId"].Expires = DateTime.Now.AddDays(-2.0);
                    HttpContext.Current.Request.Cookies.Remove("ASP.NET_SessionId");
                    HttpContext.Current.Request.Cookies.Add(cookie);
                }
            }
}

Step 2:  Add to Global.ascx  

if you have any logout button then add it to Button Click event to remove session. otherwise only add this section to Global.ascx




 void Session_End(object sender, EventArgs e)
    {
        // Code that runs when a session ends. 
        // Note: The Session_End event is raised only when the sessionstate mode
        // is set to InProc in the Web.config file. If session mode is set to StateServer 
        // or SQLServer, the event is not raised.

        Session.Clear();
        Session.Abandon();
        Guid guid = Guid.NewGuid();

        if (HttpContext.Current != null)
        {
            if (HttpContext.Current.Request.Cookies["ASP.NET_SessionId"] != null)
            {
                string text1 = HttpContext.Current.Request.Cookies["ASP.NET_SessionId"].Value;
                HttpCookie cookie = HttpContext.Current.Request.Cookies["ASP.NET_SessionId"];
                cookie.Value = guid.ToString();
                HttpContext.Current.Request.Cookies.Set(cookie);
                string text2 = HttpContext.Current.Request.Cookies["ASP.NET_SessionId"].Value;
            }
            if (HttpContext.Current.Response.Cookies["ASP.NET_SessionId"] != null)
            {
                HttpCookie cookie2 = HttpContext.Current.Response.Cookies["ASP.NET_SessionId"];
                cookie2.Value = guid.ToString();
                HttpContext.Current.Response.Cookies.Set(cookie2);
                string text3 = HttpContext.Current.Response.Cookies["ASP.NET_SessionId"].Value;
            }
            HttpContext.Current.Request.Cookies["ASP.NET_SessionId"].Expires = DateTime.Now.AddDays(-2.0);
            HttpContext.Current.Response.Cookies["ASP.NET_SessionId"].Expires = DateTime.Now.AddDays(-2.0);
        }


    }