/* layers.js                                   */
/* Copyright 2004 by Creative Element          */
/* All rights reserved                         */
/*                                             */
/* based on code by Sharon Paine and Mike Hall */



var CurrentLayer;	// holds id of currently visible layer

function swapLayers(LayerID) {
  if (CurrentLayer) hideLayer(CurrentLayer);
  showLayer(LayerID);
  CurrentLayer = LayerID;
}

function showLayer(LayerID) {
  var lyr = getElemRefs(LayerID);
  if (lyr && lyr.css) {

  	lyr.css.visibility = "visible";
  	lyr.css.height = "auto";
  }
}

function hideLayer(LayerID) {
  var lyr = getElemRefs(LayerID);
  if (lyr && lyr.css) {
  	
  	lyr.css.visibility = "hidden";
  	lyr.css.height = "1px";
  }
}

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

function getLyrRef(lyr,doc) {

// get reference to nested layer for ns4

	if (document.layers) {
		var theLyr;
		for (var i=0; i<doc.layers.length; i++) {
	  	theLyr = doc.layers[i];
			if (theLyr.name == lyr) return theLyr;
			else if (theLyr.document.layers.length > 0) 
	    	if ((theLyr = getLyrRef(lyr,theLyr.document)) != null)
					return theLyr;
	  }
		return null;
  }
}