problem with response

Hello,
I´m use AW.HTTP.Request to invoke a method of my web service.
request() method runs ok, but I do not manage to recover the value that my web service returns to me (it is a boolean value).
I try this:

function EjecutarServicioSincrono(nomServicio, Empresa, CodArt, DescArt, Precio, Stock, CodPro){
//Funcion empleada para ejecutar el servicio "EjecutaSQL" de manera sincrona (usando HttpRequest de AW)
var req = new AW.HTTP.Request;
req.setURL("webservice.asmx/" + nomServicio);
req.setParameter('Empresa', Empresa); // Establecemos los parametros que le pasamos al servicio
req.setParameter('CodArt', CodArt);
req.setParameter('DescArt', DescArt);
req.setParameter('Precio', Precio);
req.setParameter('Stock', Stock);
req.setParameter('CodPro', CodPro);
req.setAsync(false); // Hace una peticion sincrona
req.setRequestMethod("POST");
req.request(); //Hacemos la peticion al web service

alert(req.getResponseText());
}

What do you get in responseText?

I believe that I get a xml table (or something similar, I have never use HTTP.Request).
I send you and e-mail with my screen. I don´t know how to extract the boolean value that appears in this table