public timer()
    {
        tm = new System.Timers.Timer(18 * 60 * 1000);
        tm.Enabled = true;
        tm.Elapsed += new System.Timers.ElapsedEventHandler(this.tm_Elapsed);}
protected void tm_Elapsed(object sender, System.Timers.ElapsedEventArgs e)
    {System.Net.WebClient objHTTP = new System.Net.WebClient();
        String strURL = "http://www.miosito.it/Default.aspx";
        objHTTP.DownloadData(strURL);

    }