OpenLayers: WFS in Verbindung mit OSM

HTML

<script src="http://cdnjs.cloudflare.com/ajax/libs/openlayers/2.13.1/OpenLayers.js"></script>
<body onload="init()">OpenLayers: WFS in Verbindung mit OSM
    <div id="map" class="smallmap"></div>
    
    
</body>

CSS

#map {
    width: 400px;
    height: 400px;
    border: 1px solid #dddddd;
}

JavaScript

var map;
var layer,osm;

function init() {
    map = new OpenLayers.Map('map',
                             {                           maxExtent: new OpenLayers.Bounds(0,0,0,0)
});
    osm = new OpenLayers.Layer.OSM();
   


    layer = new OpenLayers.Layer.Vector("WFS", {
        strategies: [new OpenLayers.Strategy.BBOX()],
        protocol: new OpenLayers.Protocol.WFS({
            url: "http://geospatial.ga:8080/geoserver/newdata/ows",
            version: "1.0.0",
            featureType: "missouri_building",
            // layername: osm:ne_10m_populated_places
            // prefix osm: not needed, as we declare the featureNS
            featureNS: "http://geospatial.ga"
        })
    });


    map.addLayers([osm, layer]);
    map.setCenter(new OpenLayers.LonLat(12.5, 52.5).transform("EPSG:4326","EPSG:3857"), 7);



}