var mis_imagenes = new Array("images/header/1.jpg",
                             "images/header/2.jpg",
                             "images/header/3.jpg",
                             "images/header/4.jpg",
                             "images/header/5.jpg",
                             "images/header/6.jpg",
                             "images/header/7.jpg",
                             "images/header/8.jpg");
var mi_imagen = 0;
var imgCt = mis_imagenes.length;

function rotacion() {
	if (document.images) {
		mi_imagen++;
		if (mi_imagen == imgCt) {
			mi_imagen = 0;
		}
		document.banner.src=mis_imagenes[mi_imagen];
		setTimeout("rotacion()", 4 * 1000);	
	}
}