rnd.today = new Date();
rnd.seed = rnd.today.getTime();

function rnd() {
  rnd.seed = (rnd.seed*9301+49297) % 233280;
  return rnd.seed/(233280.0);
};

function rand(number) {
  return Math.ceil(rnd()*number);
};

document.write("<img src='../engimages/image" + rand(15) + ".jpg'>");