BrowserFullScreen = function()
{
  window.fullScreen = !window.fullScreen;

  document.getElementById('navigator-toolbox')
          .setAttribute('hidden', (window.fullScreen) ? 'true' : 'false');

  document.getAnonymousElementByAttribute(gBrowser, 'anonid', 'tabcontainer')
          .setAttribute('hidden', (window.fullScreen) ? 'true' : 'false');
}