How to change "charset=utf-8" or "encoding=utf-8" to other charsets or encodings?

[ajax chelsea]

POST /wstest/NetWebService/SampleService HTTP/1.1
Host: localhost
Content-Type: text/xml; charset=utf-8  <!--1, how can I change it to charset=shift_jis using axis? Thanks-->
Content-Length: length
SOAPAction: "http://tempuri.org/max"

<?xml version="1.0" encoding="utf-8"?> <!--2, how can I change it to encoding="shift_jis" using axis? Thanks-->
<soap:Envelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema
" xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">
  <soap:Body>
    <max xmlns="http://tempuri.org/">
      <a>int</a>
      <b>int</b>
    </max>
  </soap:Body>
</soap:Envelope>
 
Assume the operation name is not "max", but a japanese string, and I prefer shift_jis to utf-8, then what should I do?
Thanks.