function setActive(index)
{
  var parentTop = document.getElementById('ParentTop');
  var childTop = document.getElementById('ChildTop');
  var categories = parentTop.getElementsByTagName('a');
  for(var i=0;i<categories.length;i++)
  {
    var active = "";
    if(i==index)
      active = "active";

    categories[i].className = active;
    categories[i].onmouseover = function()
    {
      setActive(this.id);
    };
  }
  var itemLists = childTop.getElementsByTagName('div');
  for(var i=0;i<itemLists.length;i++)
  {
    var style = "none"
    if(i==index)
      style = "block";

    itemLists[i].style.display = style; 
  }
}