Preferences.remove("Proxy.listener." + key + ".primary");
    public boolean removeListener(String key) {        Listener l = (Listener) _listeners.get(key);        if (l == null) return false;        if (stopListener(l)) {            _listeners.remove(key);            if (_ui != null) _ui.proxyRemoved(key);            Preferences.remove("Proxy.listener." + key + ".base");            Preferences.remove("Proxy.listener." + key + ".useplugins");            Preferences.remove("Proxy.listener." + key + ".simulator");            String value = null;            Iterator i = _listeners.keySet().iterator();            while (i.hasNext()) {                key = (String) i.next();                if (value == null) {                    value = key;                } else {                    value = value + ", " + key;                }            }            if (value == null) {                value = "";            }            Preferences.setPreference("Proxy.listeners", value);            return true;        } else {            return false;        }    }