Nwton

<ul>
	<li>1</li>
	<li>2</li>
	<li>3</li>
<ul>

li{
	display: none;
}

window.onload = function(){
	show();
}

function show(){
	var list = document.getElementsByTagName('li');
	list[rand(0, list.length - 1)].style.display = 'block';
}

function rand(min, max){
	return Math.floor(Math.random() * (max - min + 1)) + min;
}