SOAP Validation Help Requested

[Robert Liguori]

This code:

<?xml version="1.0" encoding="UTF-8"?>
<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/"
xmlns:xsd="http://www.w3.org/2001/XMLSchema"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
    <soapenv:Body>
        <add xmlns="http://calculator.me.org/" >
            <i xmlns="">4.0</i>
            <j xmlns="">2.0</j>
        </add>
    </soapenv:Body>
</soapenv:Envelope>

Produces this error when validated with NetBeans:

XML validation started.
Checking ../soapXmlDocument.xml...
cvc-elt.1: Cannot find the declaration of element 'soapenv:Envelope'. [4] 
XML validation finished.

Any ideas why?

Thanks!