ASP.NET - Tratamiento de errores con UpdatePanel

 protected void ScriptManager1_AsyncPostBackError(object sender, AsyncPostBackErrorEventArgs e)
    {
        string msgError = ScriptManager1.AsyncPostBackSourceElementID.Split('$')[0];
        if (msgError != null)
            ScriptManager1.AsyncPostBackErrorMessage = "****" + msgError;
       
        //Label labelError = (Label)ScriptManager1.Page.FindControl("LabelError");
        //labelError.Text = e.Exception.Message;
    }