var current_link;
function doLinkClass(link) {
  if (link && link.blur) link.blur();
  if (!link || current_link == link) return;
  if (current_link) current_link.className = "done";
  link.className = "on";
  current_link = link;
}

var current_layer;
function swapLayers(link,id) {
  doLinkClass(link);
  if (current_layer) hideLayer(current_layer);
  showLayer(id);
  current_layer = id;
}

function isOpera()
{
  return (navigator.userAgent.toLowerCase().indexOf('opera') != -1);
}

function showLayer(id) {
  var layer = getElemRefs(id);
  if (layer && layer.css) layer.css.display = "block"+(isOpera() ? " !important" : "");
}

function hideLayer(id) {
  var layer = getElemRefs(id);
  if (layer && layer.css) layer.css.display = "none";
}

function getElemRefs(id) {
	var el = (document.getElementById)? document.getElementById(id): (document.all)? document.all[id]: (document.layers)? getlayerRef(id,document): null;
	if (el) el.css = (el.style)? el.style: el;
	return el;
}

function init(id,layer) {
  var link = getElemRefs(id);
  swapLayers(link,layer);
}