SOAP Namespace Prefix

Good pm!

Client is interfacing with me through web service. My soap response looks like this

<?xml version="1.0" encoding="utf-8"?>

<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/">

  <soapenv:Body>

    <ns:WhatPasswordResponse xmlns:ns="http://ws">

      <ns:return>password </ns:return>

    </ns:WhatPasswordResponse>

  </soapenv:Body>

</soapenv:Envelope>

but client is expecting it to look like this

<?xml version=”1.0” encoding=”UTF-8”?>

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

<SOAP-ENV:Body>

    <ns2:WhatPasswordResponse xmlns:ns2="http://ws">

      <ns2:return>password </ns2:return>

    </ns2:WhatPasswordResponse>

</SOAP-ENV:Body>

</SOAP-ENV:Envelope>

I have already tried passing xml as string, but client does not like that.Is there a way to do this? Your help would be most appreciated. Thank you!