function showLayer(id) {
  var lyr = getElemRefs(id);
  if (lyr && lyr.css) lyr.css.display = "block";
}

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

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

var cur_lyr;	// holds id of currently visible layer
function swapLayers(id) {
  if (cur_lyr) hideLayer(cur_lyr);
  showLayer(id);
  cur_lyr = id;
}

var lastDiv = "";
function showDiv(divName) {
	// hide last div
	if (lastDiv) {
		document.getElementById(lastDiv).className = "hiddenDiv";
	}
	//if value of the box is not nothing and an object with that name exists, then change the class
	if (divName && document.getElementById(divName)) {
		document.getElementById(divName).className = "visibleDiv";
		lastDiv = divName;
	}
}