PHP肥皂响应返回NaN

i'm sorry if the title might misleading, i'm kinda dumb but could you give me a little hint for me.

i'm trying for bmi web service

soap request

 POST /webservices/bmiservice.asmx HTTP/1.1
    Host: www.beetledev.com
    Content-Type: text/xml; charset=utf-8
    Content-Length: length
    SOAPAction: "http://www.beetledev.com/getBmiValue"

   <?xml version="1.0" encoding="utf-8"?>
   <soap:Envelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">
      <soap:Body>
        <getBmiValue xmlns="http://www.beetledev.com">
          <w>double</w>
          <h>double</h>
        </getBmiValue>
      </soap:Body>
    </soap:Envelope>

soap response

HTTP/1.1 200 OK
   Content-Type: text/xml; charset=utf-8
   Content-Length: length

   <?xml version="1.0" encoding="utf-8"?>
   <soap:Envelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"    xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">
     <soap:Body>
       <getBmiValueResponse xmlns="http://www.beetledev.com">
         <getBmiValueResult>double</getBmiValueResult>
       </getBmiValueResponse>
     </soap:Body>
    </soap:Envelope>

PHP coding

<?php
require_once "lib/nusoap.php";
$client = new nusoap_client("http://www.beetledev.com/webservices/bmiservice.asmx");

$error = $client->getError();
if ($error) {
    echo "<h2>Constructor error</h2><pre>" . $error . "</pre>";
}

$result = $client->call('getBmiValue',array('w' => 62, 'h' =>167),null, 'http://www.beetledev.com/getBmiValue');


if ($client->fault) {
    echo "<h2>Fault</h2><pre>";
    print_r($result);
    echo "</pre>";
}
else {
    $error = $client->getError();
    if ($error) {
        echo "<h2>Error</h2><pre>" . $error . "</pre>";
    }
    else {
        echo "<h2>BMI</h2><pre>";
        echo $result;
        echo "</pre>";
    }
}

echo "<h2>Request</h2>";
echo "<pre>" . htmlspecialchars($client->request, ENT_QUOTES) . "</pre>";
echo "<h2>Response</h2>";
echo "<pre>" . htmlspecialchars($client->response, ENT_QUOTES) . "</pre>";
?>

result

BMI

NaN

Request

POST /webservices/bmiservice.asmx HTTP/1.0
Host: www.beetledev.com
User-Agent: NuSOAP/0.9.5 (1.123)
Content-Type: text/xml; charset=UTF-8
SOAPAction: "http://www.beetledev.com/getBmiValue"
Content-Length: 476

<?xml version="1.0" encoding="UTF-8"?><SOAP-ENV:Envelope SOAP-ENV:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/" xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:SOAP-ENC="http://schemas.xmlsoap.org/soap/encoding/"><SOAP-ENV:Body><getBmiValue><w xsi:type="xsd:int">62</w><h xsi:type="xsd:int">167</h></getBmiValue></SOAP-ENV:Body></SOAP-ENV:Envelope>

Response

HTTP/1.1 200 OK
Cache-Control: private, max-age=0
Content-Type: text/xml; charset=utf-8
Server: Microsoft-IIS/8.5
X-AspNet-Version: 2.0.50727
X-Powered-By: ASP.NET
Date: Sun, 27 Apr 2014 14:26:40 GMT
Connection: close
Content-Length: 364

<?xml version="1.0" encoding="utf-8"?><soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema"><soap:Body><getBmiValueResponse xmlns="http://www.beetledev.com"><getBmiValueResult>NaN</getBmiValueResult></getBmiValueResponse></soap:Body></soap:Envelope>

i dont know where i do wrong, i'm hoping for a little hint

Thank you

i found the solution to my problem

first

$client = new nusoap_client("http://www.beetledev.com/webservices/bmiservice.asmx");

change to

$client = new nusoap_client('http://www.beetledev.com/webservices/bmiservice.asmx?WSDL',TRUE);

second

$result = $client->call('getBmiValue',array('w' => 62, 'h' =>167),null, 'http://www.beetledev.com/getBmiValue');

change to

$result = $client->call('getBmiValue',array('w' => 62,'h'   => 167));

third

the thing is because there are two variable? (not sure with term), so it was kept in an array

please dont mind the variable name

$fConversionRate = (float) $result['getBmiValueResult'];

and done and i get my bmi result.