/*************************************************************************
  This code is from Dynamic Web Coding at http://www.dyn-web.com/
  Copyright 2001-3 by Sharon Paine
  See Terms of Use at http://www.dyn-web.com/bus/terms.html
  regarding conditions under which you may use this code.
  This notice must be retained in the code as is!
*************************************************************************/


// Parche para el resize en ns4
var origWidth, origHeight;
if (document.layers) {
origWidth = window.innerWidth; origHeight = window.innerHeight;
window.onresize = function() { if (window.innerWidth != origWidth || window.innerHeight != origHeight) history.go(0); }
}

var cur_lyr;    // retiene el id de la capa visible
function swapLayers(id) {
  if (cur_lyr) hideLayer(cur_lyr);
  showLayer(id);
  cur_lyr = id;
}

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

function hideLayer(id) {
  var lyr = getElemRefs(id);
  if (lyr && lyr.css) lyr.css.visibility = "hidden";
}

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

// get reference to nested layer for ns4
// from old dhtmllib.js by Mike Hall of www.brainjar.com
function getLyrRef(lyr,doc) {
  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;
  }
}