function offTimer() {
	if (document.timer) {
		window.clearTimeout(document.timer);
		document.timer = null;
	}
}

function show(obj) {
	document.getElementById('sub' + obj).style.display = 'block';
	document.getElementById('item' + def).className = 'btn';
	document.getElementById('item' + obj).className = 'btn2';
}

function hide() {
	if (document.vis_l3) {
			document.getElementById(document.vis_l3).style.display = 'none';
			document.vis_l3 = null;
		};
	document.getElementById('sub' + document.vis).style.display = 'none';
	document.getElementById('item' + document.vis).className = 'btn';
	document.getElementById('item' + def).className = 'btn2';
}
function on(obj) {
	offTimer();
	if (document.vis) {
		hide();
	}
	show(obj);
}

function off(obj) {
	document.vis = obj;
	document.timer = window.setTimeout('hide()', 300);
}

function preload(obj) {
	new Image().src = obj;
};