function getRandomFile() {
	var req = new XMLHttpRequest();
	req.open("get", "http://glassocean.net/media/background/rotate.php", true);
	req.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
	req.send("");
	// use a callback function to get the response
	req.onreadystatechange = function()
	{
		if (req.readyState == 4) {
			if (req.status == 200) {
				// process
				callback(req);
			}
		}
	}
}
function callback(req) {
	var body = document.getElementsByTagName("body")[0];
	var x = "";
	var r = req.responseText;
	r = r.replace(/[\r\n]+/g, "");
	x = "background-image: url(" + "'" + "/media/background/" + r + "');";
	body.setAttribute("style", x);
}