function showLayer(layerName) {
	if (document.getElementById) {
		var targetElement = document.getElementById(layerName);
		targetElement.style.display = 'inline';
	}
}
function hideLayer(layerName) {
	if (document.getElementById) {
		var targetElement = document.getElementById(layerName);
		targetElement.style.display = 'none';
	}
}