function toggle_details(id) {
  var visible = Element.visible('toggle-details-' + id);
  Element[(visible ? 'remove' : 'add') + 'ClassName']('toggle-' + id, 'active');
  
  if (visible) {
    $('toggle-twister-' + id).src = $('toggle-twister-' + id).src.replace(/open/, 'closed');
  } else {
    $('toggle-twister-' + id).src = $('toggle-twister-' + id).src.replace(/closed/, 'open');
  }

  new Effect.toggle('toggle-details-' + id, 'slide', { duration: .5 });
}