How can we set status flag to false for log in users , when session Expires

1.For session expiration, you could do this by managing Session_End event in MvcApplication class from your Global.asax.cs, like in the next example:

protected void Session_End(object sender, EventArgs e)
       {
           SiteSession siteSession = (Session["SiteSession"] == null ? null : (SiteSession)Session["SiteSession"]);
           using (MvcBasicSiteEntities db = new MvcBasicSiteEntities())
           {
               //Update the visitor log entry!
               VisitorLog.OnUserLogoff(db, (siteSession == null ? 0 : siteSession.VisitorLogID), true);
           }
       }

2.For browser closing you should do it by using JavaScript and AJAX call from your layout (_Layout.cshtml) like in the next example:

<script type="text/javascript">
        
        function onWindowClosing() {
            if (window.event.clientX < 0 || window.event.clientY < 0) {
                $.ajax({
                    type: "POST",
                    url: "/Account/OnWindowClosing"
                });
            }
        };

        function onKeydown(evt) {
            if (evt != undefined && evt.altKey && evt.keyCode == 115) //Alt + F4 
            {
                $.ajax({
                    type: "POST",
                    url: "/Account/OnWindowClosing"
                });
            }
        };

        window.onbeforeunload = onWindowClosing;
        window.document.onkeydown = onKeydown; 
       
    </script>

And in the controller the action for managing the browser closing will invoke the same method from business logic for updating the visitors log.

public void OnWindowClosing()
        {
            SiteSession siteSession = this.CurrentSiteSession;
            VisitorLog.OnUserLogoff(_db, (siteSession == null ? 0 : siteSession.VisitorLogID), false);
            //
            Session.Clear(); // This is like a user log off!
        }

3.For details and source code about all of these you could use my next article: MVC Basic Site: Step 4 – jqGrid Integration in MVC 4.0 using AJAX, JSON, jQuery, LINQ, and Serialization[^]