// link style change
	var cur_link;
	function doLinkClass(lnk) {
	  if (!lnk || cur_link == lnk) return;
	  if (cur_link) cur_link.className = "itemOff";
	  lnk.className = "itemOn";
	  cur_link = lnk;
	}

	var cur_lyr;	// holds id of currently visible layer
	function swapMe(lnk,id) {
	  doLinkClass(lnk);
	  if (cur_lyr) hideMe(cur_lyr);
	  showMe(id);
	  cur_lyr = id;
	}

	function showMe(id) {
	  var lyr = document.getElementById(id);
	  if (lyr && lyr.style) lyr.style.display = "block";
	}

	function hideMe(id) {
	  var lyr = document.getElementById(id);
	  if (lyr && lyr.style) lyr.style.display = "none";
	}
	
	function init(id,lyr) {
  var lnk = document.getElementById(id);
  swapMe(lnk,lyr);
}