Probs with validating against XML-Schmea with Xerces

Hi folks,

I´ve downloaded the latest Xerces 1.4.1 and wanted to validate an XML-document against an XML-Schema.
My problem is, that Schema ist totally ignored.

The head of my XML-document is:

<a:bonds xmlns:a="http://www.aifb.uni-karlsruhe.de"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
  xsi:schemaLocation="file:///c:bonds.xsd">

and the head of the XML-Schema is:

<schema xmlns="http://www.w3.org/2001/XMLSchema"
        xmlns:a="http://www.aifb.uni-karlsruhe.de"
        targetNamespace="http://www.aifb.uni-karlsruhe.de"
        elementFormDefault="qualified"
        attributeFormDefault="unqualified">

My Java programm instantiates a DOMParser and the ErrorHandler is also properly implemented.

So what is my mistake ?

Thanks in advance

Best Regards

Uwe