Problems updating BP record with SOAP

Question

Trying to update a business partner record with the SOAP env. below I get the error message: "Key not supplied". Where in the XML should I insert the key (CardCode) of the business partner I wish to update?
<?xml version="1.0" encoding="UTF-16"?>
<env:Envelope xmlns:env="http://www.w3.org/2003/05/soap-envelope">
<env:Header>
<SessionID>A9DE2062-4F96-F9E1-DE3C-81E0DB23F174</SessionID>
</env:Header>
<env:Body>
<dis:UpdateObject xmlns:dis="http://www.sap.com/SBO/DIS">
<BOM>
<BO>
<AdmInfo>
<Object>oBusinessPartners</Object>
</AdmInfo>
<BusinessPartners>
<row>
<CardCode>31177</CardCode>
<FederalTaxID>987280115</FederalTaxID>
</row>
</BusinessPartners>
</BO>
</BOM>
</dis:UpdateObject>
</env:Body>
</env:Envelope>

Answer 1

For those interested I succsesfully managed to update a business partner record  with the follwing XML:
(Replace $session_id with valid session id)
[code]<?xml version="1.0" encoding="UTF-16"?>
<env:Envelope xmlns:env="http://schemas.xmlsoap.org/soap/envelope/">
     <env:Header>
          <SessionID>$session_id</SessionID>
     </env:Header>
     <env:Body>
          <dis:UpdateObject xmlns:dis="http://www.soap.com/SBO/DIS">
               <BOM>
                    <BO>
                         <AdmInfo>
                              <Object>2</Object>
                              <Version>2</Version>
                         </AdmInfo>
                         <QueryParams>
                              <CardCode>30001</CardCode>
                         </QueryParams>
                         <BusinessPartners>
                              <row>
                                   <ZipCode>5265</ZipCode>
                              </row>
                         </BusinessPartners>
                    </BO>
               </BOM>
          </dis:UpdateObject>
     </env:Body>
</env:Envelope>
[/code]