function updateLayers(params) {
var layerParam = params.layers || "M";
+ var layersAdded = "";
for (var i = layers.length - 1; i >= 0; i--) {
if (layerParam.indexOf(layers[i].options.code) >= 0) {
map.addLayer(layers[i]);
+ layersAdded = layersAdded + layers[i].options.code;
+ } else if (i == 0 && layersAdded == "") {
+ map.addLayer(layers[i]);
} else {
map.removeLayer(layers[i]);
}