-have attached WSDL
-load it into web service tester

=> generated sample message is:

<?xml version="1.0" encoding="utf-8" standalone="yes" ?>
<soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" >
<soap:Body>
<minusOperation xmlns = "http://www.example.org/ws/">
<parameters>?</parameters>
<header>?</header>
</soap:Body>
</soap:Envelope>

but should be (or should be equivalent to):

<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:squ="http://www.example.org/ws/square/" xmlns:bas="http://www.example.org/ws/basic/">
<soapenv:Header>
<squ:storeHeader>
<id>?</id>
<timestamp>?</timestamp>
</squ:storeHeader>
</soapenv:Header>
<soapenv:Body>
<bas:operationRequest>
<a>?</a>
<b>?</b>
</bas:operationRequest>
</soapenv:Body>
</soapenv:Envelope>