Checking/Reporting on Many Nodes

Gang,
 I'm new to Schematron (glad I found it!) and I'm a little stuck. Here's the
deal...I have a document that I'm checking that looks like this:

<Message>
 <Product>
   <REF>1</REF>
   <AAA>Test1</AAA>
   <BBB>Test1</BBB>
 </Product>
 <Product>
   <REF>2</REF>
   <AAA>Test2</AAA>
   <BBB>Test2</BBB>
   <CCC>Test2</CCC>
 </Product>
</Message>

I'm checking for the presence of some elements, attributes and some data
checking and that seems to work fine. However, my document can contain a lot of
<Product> nodes (thousands) and when one of checks fails I would like to know
which <Product> node had the error. I'm pretty sure I can reference the <REF>
element (which is unique) in some manner to give me the 'location' of the error,
but I'm stumped as to how to do that. Right now my schema 'tests' the document
and gives me a list of errors, but not where those errors are.

Any help is appreciated, 

-- 
Noah Genner
[email protected]
http://www.genner.on.ca/noahville/


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