AGPLibrary.PanelMenu = {
  toggle: function(source)
  {
    var submenu = AGPLibrary.getParent(source);
    var content = AGPLibrary.getTarget(submenu, "content");
    var disclosed = (dojo.style(content, 'display') == 'block');
    dojo.style(content, 'display', (disclosed ? 'none' : 'block'));
    dojo.toggleClass(submenu, 'disclosed');
  }
}