Automatic Logout when session is timeout in vb.net

Automatic Logout when session is timeout in vb.net:

To do this I am use a user control and use the user control in master page.

<%@ Control Language="VB" AutoEventWireup="false" CodeFile="AutoLogout.ascx.vb" Inherits="UserControl_AutoLogout" %>
<script type="text/javascript">
    var timeRefresh;
    var timeInterval;
    var currentTime;
    var expressTime;

    expressTime = "<%=ExpressDate %>";
    currentTime = "<%=LoginDate %>";
    setCookie("express", expressTime);
    timeRefresh = setInterval("Refresh()", 30000);

    // Refresh this page to check session is expire or timeout.
    function Refresh() {
        var current = getCookie("express");
        var date = current.split(" ")[0];
        var time = current.split(" ")[1];
        var scriptDate = new Date();
        var year = scriptDate.getFullYear();
        var month = scriptDate.getMonth() + 1;
        var day = scriptDate.getDate();
        var hour = scriptDate.getHours();
        var min = scriptDate.getMinutes();
        var second = scriptDate.getSeconds();
        if (Date.UTC(year, month, day, hour, min, second) >=
           Date.UTC(date.split("-")[0], date.split("-")[1], date.split("-")[2],
           time.split(":")[0], time.split(":")[1], time.split(":")[2])) {
            clearInterval(timeRefresh);
            Redirect();
        }
    }

    function Redirect() {
        window.location.replace("index.aspx?info=1");
    }

    // Retrieve cookie by name.
    function getCookie(name) {
        var arg = name + "=";
        var aLen = arg.length;
        var cLen = document.cookie.length;
        var i = 0;
        while (i < cLen) {
            var j = i + aLen;
            if (document.cookie.substring(i, j) == arg) {
                return getCookieVal(j);
            }
            i = document.cookie.indexOf(" ", i) + 1;
            if (i == 0) break;
        }
        return;
    }

    function getCookieVal(offSet) {
        var endStr = document.cookie.indexOf(";", offSet);
        if (endStr == -1) {
            endStr = document.cookie.length;
        }
        return unescape(document.cookie.substring(offSet, endStr));
    }

    // Assign values to cookie variable.
    function setCookie(name, value) {
        document.cookie = name + "=" + escape(value);
    }
</script>
--------------------
VB Code:
Imports System.Globalization

Partial Public Class UserControl_AutoLogout
    Inherits System.Web.UI.UserControl

    Public LoginDate As String
    Public ExpressDate As String

    Protected Sub Page_Load(sender As Object, e As EventArgs) Handles Me.Load
        If HttpContext.Current.Session("uname") = Nothing Then
            Response.Redirect("index.aspx?info=0")
        End If

        ' '''Get user login time or last activity time.
        Dim date0 As DateTime = DateTime.Now
        LoginDate = date0.ToString("u", DateTimeFormatInfo.InvariantInfo).Replace("Z", "")
        Dim sessionTimeout As Integer = Session.Timeout
        Dim dateExpress As DateTime = date0.AddMinutes(sessionTimeout)
        ExpressDate = dateExpress.ToString("u", DateTimeFormatInfo.InvariantInfo).Replace("Z", "")

    End Sub
End Class
------------------
In master page add this:
<%@ Register src="~/UserControl/AutoLogout.ascx" tagname="AutoRedirect" tagprefix="uc1" %>

Add this in from tag:
<uc1:AutoRedirect ID="AutoRedirect1" runat="server" />

Set session timeout in web.config file:
<sessionState timeout="30"/>