[bes]

<style>
div button {
	visibility: hidden;
}
</style>
<div>
	<button>1</button>
	<button>2</button>
	<button>3</button>
</div>
<script>
window.onload = function () {
	var div = document.body.children[0];
	var elems = div.children;
	var len = elems.length;
	var n, m = 0;
	setInterval(function () {
		n = m - 1;
		if (n < 0) {
			n = len - 1;
		}
		elems[n].style.visibility  = 'hidden';
		elems[m].style.visibility  = 'visible';
		m++;
		if (m > len - 1) {
			m = 0;
		}
		
	}, 1000);
	
}
</script>