static void OnSyncDialogResponse (object sender, Gtk.ResponseArgs args)
{
((Gtk.Widget) sender).Destroy ();
sync_dlg = null;
}
static void OpenNoteSyncWindow (object sender, EventArgs args)
{
if (sync_dlg == null) {
sync_dlg = new SyncDialog ();
sync_dlg.Response += OnSyncDialogResponse;
}
sync_dlg.Present ();
}