function randomize(min, max) {
	if (!min)
		min = 0;
	if (!max)
		max = 1;
	return Math.floor(Math.random()*(max+1)+min);
}
function randombg() {
	var bgs = new Array();
 
	bgs.push("/Images/metroimages/bg/green_screen_lights.jpg");
	bgs.push("/Images/metroimages/bg/green_screen.jpg");
	bgs.push("/Images/metroimages/bg/hall.jpg");
	bgs.push("/Images/metroimages/bg/lab.jpg");
	bgs.push("/Images/metroimages/bg/meeting.jpg");
	bgs.push("/Images/metroimages/bg/open-day.jpg");
	bgs.push("/Images/metroimages/bg/keyboard.jpg");

	document.body.style.backgroundImage = "url(" + bgs[randomize(0, bgs.length-1)] + ")";
}