private void createJson()
    {
        InmueblesBLL bllinmuebles = new InmueblesBLL();
        dt = bllinmuebles.SelectAllInmueblesMapaPublico();
        int count = 0;
        int position = 0;
        foreach (DataRow dtRow in dt.Rows)
        {

            DateTime FechaActualiza = Convert.ToDateTime(dtRow["fechaactualiza"].ToString());
            TimeSpan diferencia = DateTime.Now - FechaActualiza;

            if (diferencia.Days <= 90)
            {
                if (dtRow["Latitud"].ToString() != "" && dtRow["Longitud"].ToString() != "")
                {
                    count++;
                }
            }
        }
        //count = 100;
        string json = "{\"count\":" + count + ",\"photos\":[";

        foreach (DataRow dtRow in dt.Rows)
        {
            DateTime FechaActualiza = Convert.ToDateTime(dtRow["fechaactualiza"].ToString());
            TimeSpan diferencia = DateTime.Now - FechaActualiza;

            if (diferencia.Days <= 90)
            {
                if (dtRow["Latitud"].ToString() != "" && dtRow["Longitud"].ToString() != "")
                {
                    position++;

                    if (dtRow["Numero"].ToString() == "900")
                    {

                    }

                    if (position < count)
                    {

                        json += "{" +
                        "\"mark_id\":\"" + dtRow["IdInmueble"].ToString() + "\"," +
                        "\"Inmueble_dir\":\"" + validateNull(dtRow["Calle"].ToString()) + " " + validateNull(dtRow["Numero"].ToString()) + "\"," +
                        "\"latitude\":" + convert(dtRow["Latitud"].ToString()) + "," +
                        "\"longitude\":" + convert(dtRow["Longitud"].ToString()) + "," +
                        "\"tipo\":\"" + dtRow["Tipo"].ToString() + "\"," +
                        "\"Piso\":\"" + validateNull(dtRow["Piso"].ToString()) + "\"," +
                        "\"Departamento\":\"" + validateNull(dtRow["Departamento"].ToString()) + "\"," +
                        "\"Operacion\":\"" + dtRow["Operacion"].ToString().Trim() + "\"," +
                        "\"nombreInmobiliaria\":\"" + dtRow["NombreInmobiliaria"].ToString() + "\"},";
                    }
                    else
                    { //if (position == count) {

                        json += "{" +
                        "\"mark_id\":\"" + dtRow["IdInmueble"].ToString() + "\"," +
                        "\"Inmueble_dir\":\"" + dtRow["Calle"].ToString() + " " + dtRow["Numero"].ToString() + "\"," +
                        "\"latitude\":" + convert(dtRow["Latitud"].ToString()) + "," +
                        "\"longitude\":" + convert(dtRow["Longitud"].ToString()) + "," +
                        "\"tipo\":\"" + dtRow["Tipo"].ToString() + "\"," +
                        "\"Piso\":\"" + validateNull(dtRow["Piso"].ToString()) + "\"," +
                        "\"Departamento\":\"" + validateNull(dtRow["Departamento"].ToString()) + "\"," +
                        "\"Operacion\":\"" + dtRow["Operacion"].ToString().Trim() + "\"," +
                        "\"nombreInmobiliaria\":\"" + dtRow["NombreInmobiliaria"].ToString() + "\"}";
                        // }
                    }

                }
            }
        }

        json += "]}";
        Response.Clear();
        Response.ContentType = "application/json; charset=utf-8";
        Response.Write(json);
        Response.End();
    }