var max = 10;
var nrImages = 5;

function makeImages() {
    this[0] = "imagens/banner/camara.gif";
    this[1] = "imagens/banner/cerebroecomunicacao.jpg";
    this[2] = "imagens/banner/cosmelind_b.jpg";
	this[3] = "imagens/banner/abuiar.jpg";
	this[4] = "imagens/banner/francinyFull.jpg";

    this.length = nrImages;
}
function makeLinks() {
    this[0] = "http://www.cmc.pr.gov.br";
    this[1] = "http://www.cerebroecomunicacao.com.br";
    this[2] = "http://www.cosmelmoveis.com.br";
	this[3] = "http://antoniobuiar.com";
	this[4]	= "http://autoescolafranciny.com.br";

    this.length = nrImages;

}
function makeAlt() {
    this[0] = "Câmara";
    this[1] = "Cérebro & Comunicação";
    this[2] = "Marcenaria";
	this[3] = "Marcas e Patentes";
	this[4] = "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;
    }
}