SOAP Header for Siebel webservice

<soapenv:Header xmlns="http://schemas.xmlsoap.org/soap/envelope/" xmlns:nss="http://siebel.com/webservices">
      <nss:UsernameToken>username</nss:UsernameToken>
      <nss:PasswordText>password</nss:PasswordText>
      <nss:SessionType>Stateless</nss:SessionType>
   </soapenv:Header>