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;    // holds id of currently visible layer
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.display = "block";
}

function showLayer2(id)
{
	var e1 = (document.getElementById)? document.getElementById(id): (document.all)? document.all[id]: (document.layers)? getLyrRef(id,document): null;
	var e2 = (document.getElementById)? document.getElementById('a'+id): (document.all)? document.all['a'+id]: (document.layers)? getLyrRef('a'+id,document): null;
	if (e1&& e2)
	{
		e1.style.top=getPosition(e2)[1]+'px';
		e1.style.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)? getLyrRef(id,document): null;
        if (el) el.css = (el.style)? el.style: el;
        return el;
}

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;
  }
}

/******************************************************************************/
/* Devuelve un array ret con la posición del elemento p_element tal que:
    ret[0]=Posición X
    ret[1]=Posición Y
*/

  function getPosition(p_element)
  {
   var positionX = 0;
   var positionY = 0;
  
   while (p_element !== null)
   {
     positionX += p_element.offsetLeft;
     positionY += p_element.offsetTop;
     p_element = p_element.offsetParent;
   }
  
   return [positionX, positionY];
  }