function showPic (whichpic) {
 if (document.getElementById) {
  document.getElementById('grande').src = whichpic.src;
  document.getElementById('agrande').href = whichpic.src;
  document.getElementById('peqa').setAttribute('ID','peq');
 	whichpic.setAttribute('ID','peqa');
  return false;
 } else {
  return true;
 }
}
function mostrar(bloq) {
  obj = document.getElementById(bloq);
  obj.style.display = (obj.style.display=='block') ? 'none' : 'block';
}
function ocultar(bloq) {
  obj = document.getElementById(bloq);
  obj.style.display = 'none';
}