Subsequent request fails

[scottydelta]

    var pnt =  {
        radius: 3,
        fillColor: "#009688",
        color: "#000",
        weight: 1,
        opacity: 1,
        fillOpacity: 0.8
    };
    var area =  {
        weight: 2,
        color: "#999",
        opacity: 1,
        fillColor: "#B0DE5C",
        fillOpacity: 0.5
    };
    parser = L.geoJson([], {
        style: function (feature) {
            return feature.properties && area;
        }
    }).addTo(map);
    var starttime = +new Date;
    shapefile = new Shapefile({
        shp: "/data/1.shp",
        dbf: "/data/1.dbf"
    }, function(data){
        features = parser.addData(data.geojson);
        console.log("took",new Date - starttime,"milliseconds")
    })
    parser1 = L.geoJson([], {
        pointToLayer: function (feature, latlng) {
            return L.circleMarker(latlng, pnt);
        }
    }).addTo(map);
    var starttime1 = +new Date;
    shapefile1 = new Shapefile({
        shp: "/data/2.shp",
        dbf: "/data/2.dbf"
    }, function(data){
        features1 = parser1.addData(data.geojson);
        console.log("took",new Date - starttime1,"milliseconds")
    })

when using the above code, only shapefile1 is visible and there is no error.