C# button click once a day
<pre><code>protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            this.GetLeft.Value = invited.GetInviteCountByWeb().ToString();
            HttpCookie oldCookie = Request.Cookies["Time"];
            if (oldCookie != null)
            {
                if (DateTime.Now.ToString("yyyy-MM-dd") == Convert.ToDateTime(oldCookie.Values["GetTime"]).ToString("yyyy-MM-dd"))
                {
                    this.IsGet.Value = "false";
                }
                else
                {
                    HttpCookie newCookie = new HttpCookie("Time");
                    newCookie.Values.Add("GetTime", DateTime.Now.Date.ToString("yyyy-MM-dd"));
                    newCookie.Expires = DateTime.Now.AddHours(24.0);
                    Response.Cookies.Add(newCookie);
                }
            }
        }
    }
</code></pre>

<p>but it's not working, the oldcookie is null when browser is closed everytime..
so how can i set button click once a day??</p>
