wanlink = nb_config_get("custom.var1");
switch(wanlink){
        case "": continue; break;
        case "WANLINK3": nb_wanlink_deactivate("WANLINK3");  nb_wanlink_activate("WANLINK4"); break;
        case "WANLINK4":  nb_wanlink_deactivate("WANLINK4"); nb_wanlink_activate("WANLINK3"); break;
        default: printf("no Hotlink"); break;
}
sleep(1);
nb_config_set("custom.var1=");