Capture de message like a operation attribute, in the content HTTP

MRs,

I need capture the message like a operation attribute, but need read the reponse message http.

the message in the body "Content" is like this:

URL response: http://banco.itau.cl/wps/portal/olb/web/login/

<div class="error-validacion" id="mensaje_cliente">
			        <div class="mensaje">
			           	<span id="msgError" name="StatusDesc" class="mensaje_error"><i class="icon-alerta icon-blanco"></i> <div class="texto_mensaje"><p>Ha ingresado un RUT o clave errónea, inténtelo nuevamente.</p></div></span>
			        </div>
			    </div>

and the message need capture is between the tag

<div class="texto_mensaje"><p>

and

</p></div>

configure the operation attribute in the some pictures

Please help for configure this response message, for category like a failure.

thanks.

ccarrasco.