var first; 

function nextAnnouncement() {
  first = $('announcements-viewport').getElementsByTagName('LI')[0]; 
  new Effect.Morph(first, { duration: 1, fps: 24, transition: Effect.Transitions.sinoidal, 
      style: 'margin-top: -110px; ', 
      afterFinish: function () {
        first.style.marginTop = 0; 
        $('announcements-viewport').removeChild(first); 
        $('announcements-viewport').appendChild(first); 
      }
  }); 
}

if ($('announcements-viewport').getElementsByTagName('LI').length > 1) {
  setInterval(nextAnnouncement, 4000)
}