function showLayer(name) {
	l = document.getElementById(name);
	if (l==null) {
		alert ('Layer '+name+' not found!');
	} else {
		l.style.display='';
	}
}

function hideLayer(name) {
	l = document.getElementById(name);
	if (l==null) {
		alert ('Layer '+name+' not found!');
	} else {
		l.style.display='none';
	}
}