Hello there,
I think Tom got confused between DTDs and XML Schema.
You need something similar to this in your instance document:
For simplicity I did not use name spaces.
<?xml version="1.0"?>
<ROOT_ELEMENT xmlns:xsd="http://www.w3.org/2001/XMLSchema-instance"
xsd:noNamespaceSchemaLocation="<your schema
doc>">
.
.
.
</ROOT_ELEMENT>