<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:book="http://tandberg.net/2004/02/tms/external/booking/">
   <soapenv:Header>
      <book:ExternalAPIVersionSoapHeader>
         <book:ClientVersionIn>22</book:ClientVersionIn>
         <!--Optional:-->
         <book:ClientIdentifierIn>?</book:ClientIdentifierIn>
         <!--Optional:-->
         <book:ClientLatestNamespaceIn>?</book:ClientLatestNamespaceIn>
         <!--Optional:-->
         <book:NewServiceURL>?</book:NewServiceURL>
         <!--Optional:-->
         <book:ClientSession>?</book:ClientSession>
      </book:ExternalAPIVersionSoapHeader>
      <book:ContextHeader>
         <book:SendConfirmationMail>false</book:SendConfirmationMail>
         <book:ExcludeConferenceInformation>true</book:ExcludeConferenceInformation>
         <!--Optional:-->
         <book:ClientLanguage>?</book:ClientLanguage>
      </book:ContextHeader>
   </soapenv:Header>
   <soapenv:Body>
      <book:DeleteConferenceById>
         <book:ConferenceId>1538</book:ConferenceId>
      </book:DeleteConferenceById>
   </soapenv:Body>
</soapenv:Envelope>