session ASP.net C# หมดอายุเองทำให้เก็บ log การ logout ไม่ได้ จะต้องแก้ไขอย่างไร

    Sub Session_End(ByVal sender As Object, ByVal e As EventArgs)
        Application.Lock()
        Application("OnlineNow") = Application("OnlineNow") - 1
        Application.UnLock()
    End Sub

using System;
using System.Collections.Generic;
using System.Data;
using System.Data.SqlClient;
using System.Web;
using System.Web.Security;
using System.Web.SessionState;

namespace eCatalog
{
    public class Global : System.Web.HttpApplication
    {
       

        protected void Application_Start(object sender, EventArgs e)
        {
          

        }

        protected void Session_Start(object sender, EventArgs e)
        {
          
        }

        protected void Application_BeginRequest(object sender, EventArgs e)
        {

        }

        protected void Application_AuthenticateRequest(object sender, EventArgs e)
        {

        }

        protected void Application_Error(object sender, EventArgs e)
        {

        }

        protected void Session_End(object sender, EventArgs e)
        {
            Application.Lock();
            Application["OnlineNow"] = (int)Application["OnlineNow"] - 1;
            Application.UnLock();
            
        }

        protected void Application_End(object sender, EventArgs e)
        {

        }
    }
}