function toggle_category (cat_id)
{
  list_id = "links-" + cat_id;
  img_id = list_id + "-image";
	list = document.getElementById(list_id)
	img = document.getElementById(img_id);
	if (list && img)
	{
	  if (list.style.display == "none")
	  {
	    list.style.display = "block";
	    img.src = "/graphics/minus_13.gif";
	  }
	  else
	  {
	    list.style.display = "none";
	    img.src = "/graphics/plus_13.gif";
	  }
	  
	  
	  init();
	}
}