function mostrarLayer(Obj)
 {
  var lay = document.getElementById(Obj);
  lay.style.visibility = 'visible';
 }

function esconderLayer(Obj)
 {
  var lay = document.getElementById(Obj);
  lay.style.visibility = 'hidden';
 }

function desaparecerLayer(Obj)
 {
  var lay = document.getElementById(Obj);
  lay.style.display = 'none';
 }

function aparecerLayer(Obj)
 {
  var lay = document.getElementById(Obj);
  lay.style.display = '';
 }
 
function muestraEsconde(id)
 {
  var cel = document.getElementById(id);
  img = "";
  if (img != "")
   var ima = document.getElementById(img);
  if (cel.style.display == 'none')
   {
    cel.style.display = '';
    if (img != "")
     {
      ima.alt = "Esconder";
      ima.src = "imgs/menos.jpg";
     }
   }
  else
   {
    cel.style.display = 'none';
    if (img != "")
     {
      ima.alt = "Mostrar";
      ima.src = "imgs/mas.jpg";
	 }
   }
 }