// -- disable control+w key in the browser ------------------------------------

var controlwKey = {
  prefName: 'browser.controlwkey.enabled',
  enabled: true,
  prefs: Components.classes['@mozilla.org/preferences-service;1']
                   .getService(Components.interfaces.nsIPrefService),
  getEnabled: function()
  {
    var enabled;

    try {
      enabled = controlwKey.prefs.getBoolPref(controlwKey.prefName);
    } catch (e) {
      enabled = true;
    }

    return enabled;
  },
  observe: function(subject, topic, data)
  {
    if (topic == 'nsPref:changed')
      this.enabled = this.getEnabled();
  },
  init: function()
  {
    controlwKey.enabled = controlwKey.getEnabled();

    var pbi = Components.classes["@mozilla.org/preferences-service;1"]
                        .getService(Components.interfaces.nsIPrefBranch2);
    pbi.addObserver(controlwKey.prefName, controlwKey, false);
  }
};

controlwKey.init();

window.addEventListener('keypress',
  function(event) {
    if (event.ctrlKey && event.which == 119 && !controlwKey.enabled) {
      event.stopPropagation();
      event.preventDefault();
    }
  }, false);