/**
  * Metodo para instanciar el servicio web 
  */
 public function webServices($url, $login = null, $password = null, $header = null, $nameSpace = null)
 {
     try {
         $socketTime = 15;
         if (!is_null($login) && !is_null($password)) {
             $this->webServices = new Soapclient($url, array('login' => $login, 'password' => $password, 'trace' => 1, 'exceptions' => true, 'cache_wsdl' => WSDL_CACHE_DISK, 'features' => SOAP_SINGLE_ELEMENT_ARRAYS, 'default_socket_timeout' => $socketTime));
         } else {
             $this->webServices = new Soapclient($url, array('trace' => 1, 'exceptions' => true, 'cache_wsdl' => WSDL_CACHE_DISK, 'features' => SOAP_SINGLE_ELEMENT_ARRAYS, 'default_socket_timeout' => $socketTime));
         }
         //Creacion de cabeceras para webServices
         if (is_object($header) && !is_null($header)) {
             $authVals = new SoapVar($header, SOAP_ENC_OBJECT);
             $header = new SOAPHeader($nameSpace, 'authenticate', $authVals);
             $this->webServices->__setSoapHeaders($header);
         }
         return true;
     } catch (SoapFault $exc) {
         throw new Exception($exc->getMessage());
     }
     return false;
 }