function preview_item(item_type, item_token) {
  try {
  $$('.' + item_type).each(function(e,idx){
    Element.hide(e);
  });
  $(item_type + '_preview_' + item_token).show();
  } catch (e) { }
} // show_banner

function select_item(item_type, item_token){
  try {
    $$('.' + item_type).each(function(e,idx){
        new Effect.Opacity(e, {duration: 0.01, to: 0.7, queue: {scope: 'stage', position: 'end'}});
        });
    new Effect.Opacity($(item_type + '_' + item_token), {duration: 0.2, to: 1.0, queue: {scope: 'stage', position: 'end'}});
  } catch (e) {
    // noop
  } // catch
}