function toggleVisibility(item)
{
  var toavoid = document.getElementById(item);
  var parent = toavoid.parentNode;
  for (child = 0; child < parent.childNodes.length; ++child)
  {
    var actualChild = parent.childNodes[child];
    if (actualChild.nodeType == 1)
    {
      if (actualChild.id != item)
      {
        actualChild.style.visibility = "hidden";
      }
      else
      {
        actualChild.style.visibility =
          (actualChild.style.visibility == "hidden") ?
          "visible" :
          "hidden";
      }
    }
  }
}