g_signal_handlers_block_by_func(combo, G_CALLBACK(on_site_changed), gui);
gtk_combo_box_set_active_iter(combo, &iter2);
g_signal_handlers_unblock_by_func(combo, G_CALLBACK(on_site_changed), gui);
g_signal_handlers_block_by_func(combo, G_CALLBACK(on_site_changed), gui);
gtk_combo_box_set_active_iter(combo, &iter2);
g_signal_handlers_unblock_by_func(combo, G_CALLBACK(on_site_changed), gui);