function setHoverOpacityEffect()
{
      listItems = document.getElementsByTagName('li');
      for(var i=0;i<listItems.length;i++)
      {
              listItems[i].setAttribute("onmouseover","new Effect.Opacity(this, { from: 0.8, to: 0.999, duration: 0.2 }); return false;");
              listItems[i].setAttribute("onmouseout","new Effect.Opacity(this, { from: 0.999, to: 0.8, duration: 0.2 }); return false;");
      }
}