<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>
