var estilo_pdi = new OpenLayers.StyleMap({
        "default": new OpenLayers.Style({
                strokeColor: "#000000",
                strokeOpacity: .7,
                strokeWidth: 3,
                fillColor: "#ff0000",
                fillOpacity: 0,
                cursor: "pointer"
                },
                {rules:[new OpenLayers.Rule({
                        title: 'id_between_1_50',
                        symbolizer: {
                        label: "${nome}",
                        externalGraphic: "../img/simbologia_layers/pdi/" + "${id}" + ".png"
                        }
                })
                ]
            }),
        "temporary": ...