ASP.NET

protected void Application_Start(Object sender, EventArgs e)
        {
            System.Data.SqlClient.SqlDependency.Stop(connectionString);
            System.Data.SqlClient.SqlDependency.Start(connectionString);
            RegisterNotification();
        }
        static SqlDependency dep;
        private static void RegisterNotification()
        {
            string tmpdata = "";
            try
            {
                using (SqlConnection conn = new SqlConnection(connectionString))
                {
                    conn.Open();
                    SqlCommand cmd = conn.CreateCommand();
                    cmd.CommandText = "SELECT ActivityDate FROM [bba-reman].ContentChangeLog";
                    dep = new SqlDependency(cmd);
                    dep.OnChange += new OnChangeEventHandler(OnDataChange);
                    SqlDataReader dr = cmd.ExecuteReader();
                    {
                        while (dr.Read())
                        {
                            if (dr[0] != DBNull.Value)
                            {
                                tmpdata = dr[0].ToString();
                            }
                        }
                    }

                    dr.Dispose();
                    cmd.Dispose();
                }
            }
            finally
            {
                //SqlDependency.Stop(connStr);
            }

        }

        static void OnDataChange(object sender, SqlNotificationEventArgs e)
        {
            SqlDependency dep = sender as SqlDependency;
            dep.OnChange -= new OnChangeEventHandler(OnDataChange);
            SiteSearch.CreateIndex(false);
            RegisterNotification();
        }

        protected void Application_End(Object sender, EventArgs e)
        {
            System.Data.SqlClient.SqlDependency.Stop(connectionString);
        }