Problems with OCS Web Service (Using C#)

Hi all,

I'm trying to use the Ocs Inventory Soap Web sevice using C#, but i got some problems. Here's my code and my errors:

If you need more info, just tell me.

https://dotnetfiddle.net/LU0SM2

And my errors:

<?xml version="1.0" encoding="UTF-8"?>
<soap:Envelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:soapenc="http://schemas.xmlsoap.org/soap/encoding/" xmlns:xsd="http://www.w3.org/2001/XMLSchema" soap:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/" xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">
    <soap:Body>
        <soap:Fault>
            <faultcode>soap:Client</faultcode>
            <faultstring>Denied access to method (get_computers_V1) in class (main) at /usr/local/share/perl/5.14.2/SOAP/Lite.pm line 2806.
            </faultstring>
        </soap:Fault>
    </soap:Body>
</soap:Envelope>