(function(){
  var overlays = {};

  Element.loading = function(element, show) {
    element = $(element);
    if (show == undefined) { show = true; }

    var overlay = overlays[element.identify()];
    if (!overlay) {
      overlay = overlays[element.identify()] = new Element('div', { style: 'position: absolute' });
      overlay.setStyle({ background: 'transparent url(/images/facebox/loading.gif) no-repeat scroll center 20%' });
      $(document.body).insert({ bottom: overlay });
      overlay.clonePosition(element);
    }

    if (show) {
      overlay.show();
      element.setOpacity(0.4);
    } else {
      overlay.hide();
      element.setOpacity(1);
    }
  };
  
  Element.addMethods({ loading: Element.loading });
})()