private String obten_select_catalogo(String nombre_catalogo) {

        ConexionBD con = new ConexionBD();
        ArrayList<String[]> elementos = con.regresaCatalogoConId(nombre_catalogo);
        String select = "";
        select = "<select id=\"select_" + nombre_catalogo + "\" name=\"select_" + nombre_catalogo + "\" style=\"display:none\">\n";

        for (String[] elemento : elementos) {
            select += "<option value=\"" + elemento[0] + "\">" + elemento[1] + "</option>\n";
        }
        select += "</select>\n";

        return select;
    }