var max      = 10;
  var nrImages = 04;
  function makeImages() {
    this[0]     = "http://static.megacubo.net/imagens/banners/468x60.jpg";    
    this[1]     = "http://www.portalbizarro.com/wp-content/uplouds/2009/10/banner_120x60_.gif";
    this[2]     = "http://static.megacubo.net/imagens/banners/468x60.jpg";
    this.length = nrImages;
    this[3]     = "http://www.portalbizarro.com/wp-content/uplouds/2010/02/FpB.gif;

}
  function makeLinks() {
    this[0]     = "www.minilua.com";
    this[1]     = "http://www.curiosidadesnanet.com/"; 
    this[2]     = "http://minilua.com/";
    this[3]     = "http://fpbturbo.com/";
    this.length = nrImages;

  }
  var vetImages = new makeImages();
  var vetLinks  = new makeLinks();
  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]+" target=_blank><img  src="+vetImages[cont-1]+" border=0></a>");
      break;
    }
  }