function showElement(el) {
	dv='nav-'+el;
	l='li-'+el;
	$(dv).setStyle({
		visibility: 'visible'
	});
	document.getElementById(l).className = "active"
}

function hideElement(el) {
	dv='nav-'+el;
	l='li-'+el;
	$(dv).setStyle({
		visibility:'hidden'
	})
	document.getElementById(l).className = "normal"
}