Javascript 代码正在禁用Mapbox工具提示

有人能看到这段代码中有什么东西阻止我的地图中的工具提示发挥作用吗？也就是说，它们在法线贴图中起作用，但在我使用切换按钮将图层添加到此贴图时不起作用。我假设它是带有onclick函数的，但无法具体地理解它，以及可能的解决方法

多谢各位

<style>
.menu-ui {
  background:#fff;
  position:absolute;
  bottom:10px;left:10px;
  z-index:1;
  border-radius:3px;
  width:120px;
  border:1px solid rgba(0,0,0,0.4);
  }
  .menu-ui a {
    font-size:13px;
    color:#404040;
    display:block;
    margin:0;padding:0;
    padding:10px;
    text-decoration:none;
    border-bottom:1px solid rgba(0,0,0,0.25);
    text-align:center;
    }
    .menu-ui a:first-child {
      border-radius:3px 3px 0 0;
      }
    .menu-ui a:last-child {
      border:none;
      border-radius:0 0 3px 3px;
      }
    .menu-ui a:hover {
      background:#f8f8f8;
      color:#404040;
      }
    .menu-ui a.active {
      background:#3887BE;
      color:#FFF;
      }
      .menu-ui a.active:hover {
        background:#3074a4;
        }
</style>
<nav id='menu-ui' class='menu-ui'></nav>
<div id='map'></div>

<script>
var map = L.map('map').setView([10.8229,-84.2116], 12);
var layers = document.getElementById('menu-ui');

addLayer(L.mapbox.tileLayer('XXXX.XXXX'), 'Photo Points', 4);
addLayer(L.mapbox.tileLayer('XXXX.XXXX'), 'River KMs', 3);
addLayer(L.mapbox.tileLayer('XXXX.XXXXX'), 'December 2013 (0.5m)', 2);
addLayer(L.mapbox.tileLayer('XXXXXX.XXXXXX'), 'February 2014 (1.5m)', 1);


function addLayer(layer, name, zIndex) {
    layer
        .setZIndex(zIndex)
        .addTo(map);

    // Create a simple layer switcher that
    // toggles layers on and off.
    var link = document.createElement('a');
        link.href = '#';
        link.className = 'active';
        link.innerHTML = name;

    link.onclick = function(e) {
        e.preventDefault();
        e.stopPropagation();

        if (map.hasLayer(layer)) {
            map.removeLayer(layer);
            this.className = '';
        } else {
            map.addLayer(layer);
            this.className = 'active';
        }
    };

    layers.appendChild(link);
}
</script>

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您是否通过添加互动功能？如果是这样的话，你需要去看地图，而不仅仅是看瓷砖