var max = 3;
var nrImages = 2;
function makeImages() {
	this[0] = "imagens/Banner/banner_natura.jpg";
	this[1] = "imagens/Banner/francinyPrincipal.jpg";
	this.length = nrImages;
}
function makeLinks() {
	this[0] = "http://www.natura.net";
	this[1] = "http://autoescolafranciny.blogspot.com";
	this.length = nrImages;
}
function makeAlt() {
	this[0] = "Natura";
	this[1] = "Franciny";
 }
var vetImages = new makeImages();
var vetLinks = new makeLinks();
var vetAlt = new makeAlt();
var x = Math.round(Math.random()*max);
var y = max / nrImages;
for(var cont = 1;cont*y<= max;cont++) {
if (x <= (cont*y)) {
document.write("<a href="+vetLinks[cont-1]+" rel='nofollow' target='_blank'><img alt="+vetAlt[cont-1]+" src="+vetImages[cont-1]+" border=0></a>");
break;
}
}