protected void Page_Init(Object sender, EventArgs e)
    {
        string xml_data = ConfigurationManager.AppSettings["tuntikirjaukset"];
        string xml_auth = ConfigurationManager.AppSettings["koodarit"];

        data = new Koodari_Data(MapPath(xml_data));
        auth = new Koodari_Auth(MapPath(xml_auth));

        ddUser.DataSource = auth.getUsers();
        ddUser.DataBind();

        string user = User.Identity.Name;
        updateList(user);
    }