function obj(name)
{
   var x = document.getElementById(name);
   return x;
}
function overTd(name)
{
   var holder = obj("sub_holder");
   var divs = holder.getElementsByTagName("div");
   for (var i=0; i<divs.length; i++)
   {
      if (divs[i].id.indexOf("_img") > 0) divs[i].style.display='block';
      if (divs[i].id.indexOf("_text") > 0) divs[i].style.display='none';
   }
   var img = obj(name.id + "_img");
   var text = obj(name.id + "_text");
   img.style.display = 'none';
   text.style.display = 'block';
}
function outTd(name)
{
   var img = obj(name.id + "_img");
   var text = obj(name.id + "_text");
   text.style.display = 'none';
   img.style.display = 'block';
}