var ids=new Array('img0','img1','img2','img3','img4','img5','img6','img7','img8','img9','img10','img11','img12');

function mostra(elm) {
	for (var i = 0; i < ids.length; i++) {
		var layer = document.getElementById(ids[i]);
		if (elm!= ids[i]) {
			layer.style.display = "none";
		}
		else {
			layer.style.display = "block";
		}
	}
}