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);
};

num = rand(4);
photoID = 'photoRotate' + num;
document.getElementById(photoID).className = 'photoRotateOn'