Hiding layers

HTML

<link rel="stylesheet" href="http://cdn.leafletjs.com/leaflet-0.7.3/leaflet.css">
<script src="http://cdn.leafletjs.com/leaflet-0.7.3/leaflet.js"></script>
<div id="map"></div>

<ul>
    <li><a id="restaurants" href="#">restaurants</a></li>
    <li><a id="sport" href="#">sport</a></li>
    <li><a id="sights" href="#">sights</a></li>
</ul>

CSS

#map { height: 480px; }

a:link {
    color: #909090;
}

a.selected:link {
    color: #101010;
}

JavaScript

// setup map
var lat = 48.185556;
var lng =  11.620278;
var zoom =  10;


var map = new L.Map('map');

var osmUrl='http://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png';
var osmAttrib='Map data &copy; OpenStreetMap contributors';
var osm = new L.TileLayer(osmUrl, {minZoom: 5, maxZoom: 18, attribution: osmAttrib});

map.addLayer(osm);
map.setView(new L.LatLng(lat, lng), zoom);

// add markers
var aa = L.marker([48.185556, 11.620278]).bindPopup('AA'),
bb = L.marker([48.152222, 11.592778]).bindPopup('BB'),
cc = L.marker([48.161209, 11.597989]).bindPopup('CC'),
dd = L.marker([48.14350, 11.58775]).bindPopup('DD'),
ee = L.marker([48.14989, 11.59094]).bindPopup('EE'),
ff = L.marker([48.15958, 11.60608]).bindPopup('FF');

var restaurants = L.layerGroup([aa, bb]);
var sport = L.layerGroup([cc, dd]);
var sights = L.layerGroup([ee, ff]);

$("#restaurants").click(function(event) {
    event.preventDefault();
    if(map.hasLayer(restaurants)) {
        $(this).removeClass('');
        map.removeLayer(restaurants);
    } else {
        map.addLayer(restaurants);        
        $(this).addClass('');
   }
});

$("#sport").click(function(event) {
    event.preventDefault();
    if(map.hasLayer(sport)) {
        $(this).removeClass('selected');
        map.removeLayer(sport);
    } else {
        map.addLayer(sport);        
        $(this).addClass('selected');
    }
});

$("#sights").click(function(event) {
    event.preventDefault();
    if(map.hasLayer(sights)) {
        $(this).removeClass('selected');
        map.removeLayer(sights);
    } else {
        map.addLayer(sights);                 
        $(this).addClass('selected');
   }
});