protected void Application_BeginRequest(object sender, EventArgs e)
        {
            string strUrl = Request.Url.ToString().Trim().ToLower();
            if (strUrl.Contains("http://phpstudy.net"))
            {
                Response.RedirectPermanent(strUrl.Replace("http://phpstudy.net", "http://www.phpstudy.net"));
            }
        }