function canvia_menu(nom, valor) {
  var x = document.images;
  var cami= "./img/" + nom + "_" + valor + ".gif";
  var img = "blank";
  x[nom].src = cami;

  if ( valor == "b") img = nom;
  cami= "./img/" + img + "_m" + ".gif";
  nom = nom + "_m";
  x[nom].src = cami;
}


function canvia_img(nom, valor) {
  var x = document.images;
  var cami= "./img/" + nom + "_" + valor + ".gif";
  var img = "blank";
  x[nom].src = cami;
}