openlayers之矢量加载标记点

    var style = new OpenLayers.Style(
        {
            graphicWidth: 30,
            graphicHeight: 30,
            //graphicYOffset: -35,
            label: "${name}",
            fontSize: "9pt",
            fontWeight: "bold",
            labelYOffset: "-20"

        },
        {
            rules: [
                new OpenLayers.Rule({

                    elseFilter: true,
                    symbolizer: {
                        externalGraphic: "${img}"
                    }
                })
            ]
        }
    );

  var  vector = new OpenLayers.Layer.Vector(vectorName, {
        styleMap: new OpenLayers.StyleMap(style)
    });
    map.addLayer(vector);

    //需要修改
    var features = new Array(400);

 var ic = "Images/Icon/car_yellow_0.png";

    for (var i = 0; i < 400; i++) {
                var sHtml = "<tr><td valign=\"top\">test</td><td valign=\"top\">" + i.toString() + "</td></tr>";
                px = Math.random() * (122 - 121 + 0.001) + 121;
                py = Math.random() * (30 - 29 + 0.001) + 29;

　　　　　var name="test"+i.toString();
                var ll = tranformTo900913(px, py);

        features[i] = new OpenLayers.Feature.Vector(
            new OpenLayers.Geometry.Point(
                lonlat.lon, lonlat.lat
            ), {
                name: name,
                img: ic,
                html: sHtml

            }
        );

    } 

    selectControl = new OpenLayers.Control.SelectFeature(vector);  //添加点击标记事件
    map.addControl(selectControl);
    selectControl.activate();

    vector.events.on({   //画popup窗
        featureselected: function (e) {
            feature = e.feature;
            popup = new OpenLayers.Popup.FramedCloud("featurePopup",
                                         feature.geometry.getBounds().getCenterLonLat(),
                                         new OpenLayers.Size(300, 300),
                                         feature.attributes.html,
                                         null, true, function (e) {

                                             selectControl.unselect(this.feature);
                                         });
            feature.popup = popup;
            popup.feature = feature;
            map.addPopup(popup);
        },
        featureunselected: function (e) {
            feature = e.feature;
            if (feature.popup) {
                popup.feature = null;
                map.removePopup(feature.popup);
                feature.popup.destroy();
                feature.popup = null;
            }
        }
    });

    vector.addFeatures(features);

}