var point = new OpenLayers.Geometry.Point(pt.lon, pt.lat);
var markerStyle = OpenLayers.Util.extend(OpenLayers.Feature.Vector.style['default'],  {
    externalGraphic: iconURL
});
var marker = new OpenLayers.Feature.Vector(point, attributes, markerStyle);

var marker = this.findSelectedMarker();
if (marker) {
    marker.style.externalGraphic = newIconUrl;
    this.layer.redraw();
}

this.layerStyle = new OpenLayers.StyleMap({
    'default': {
        externalGraphic: media_url + '${iconURL}',
        graphicHeight: 32,
        graphicWidth: 32,
        graphicXOffset: -16,
        graphicYOffset: -32,
        fillOpacity: 0.75
    }
});

focusedMarker.attributes.iconURL = this.focusedURL;
this.layer.redraw();