document.observe("dom:loaded", function() {
  if ($('sign_in_link')) {
    $('sign_in_link').observe('click', did_click_sign_in_link, false);
  }
});

function did_click_sign_in_link(e) {
  $('sign_in_panel').show();
  new Effect.Morph('download_panel', { style: { top: '-35px' }, duration: 0.3, queue: 'front'});
  new Effect.Morph('sign_in_panel', { style: { top: '0px' }, duration: 0.6, queue: 'end'});
  Event.stop(e);
}