hatterek = [
'http://www.joomlaworks.net/images/demos/galleries/abstract/7.jpg',
'http://www.joomlaworks.net/images/demos/galleries/abstract/6.jpg',
'http://www.joomlaworks.net/images/demos/galleries/abstract/5.jpg',
'http://www.joomlaworks.net/images/demos/galleries/abstract/4.jpg'
];
setInterval(function () {
var hatter = hatterek[Math.floor(Math.random()*hatterek.length)];
$('body').css('background-image', 'url(' + hatter + ')');
}, 10000);