var ban = new Array()
var indice = 0

ban[0] = new Image()
ban[0].src = "imagenes/portada1.png"

ban[1] = new Image()
ban[1].src = "imagenes/portada2.png"


ban[2] = new Image()
ban[2].src = "imagenes/portada3.png"

function rota()
{
if (indice ==  ban.length) indice = 0

if (document.images)
 {
  document.images.idfoto.src = ban[indice].src  
 }
else
 {
  document.getElementById('fotico').src=ban[indice].src
 }
indice++
setTimeout('rota()',4000)
}