var pic=new Array();
pic[0]="http://natseed.com/assets2/js/1.jpg";
pic[1]="http://natseed.com/assets2/js/2.jpg";
pic[2]="http://natseed.com/assets2/js/3.jpg";
pic[3]="http://natseed.com/assets2/js/4.jpg";
pic[4]="http://natseed.com/assets2/js/5.jpg";
pic[5]="http://natseed.com/assets2/js/6.jpg";
pic[6]="http://natseed.com/assets2/js/7.jpg";
pic[7]="http://natseed.com/assets2/js/9.jpg";
pic[8]="http://natseed.com/assets2/js/10.jpg";

var num=Math.floor(Math.random()*pic.length);

window.onload=function() {
document.getElementById('rotate').style.backgroundImage='url('+pic[num]+')';
}