$client->ns('http://soap.example.com/');

<SOAP-ENV:Envelope
	xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/"
    xmlns:namesp1="http://soap.example.com/">

<SOAP-ENV:Body>
	<namesp1:setTransaction>
		<PARAMS HERE>
	</namesp1:setTransaction>
</SOAP-ENV:Body>