Validating XML using Ada schema module

[Sonia Dalal <sonia12106@iiitd.ac.in>]

Hi all

I am new to ada. I am working on a project where I am parsing XML for data. I am trying to validate the XML received (I am receiving XML from third party) using the schema module. Following is the sample schema which I took from w3c site after I was getting raised CONSTRAINT_ERROR : schema-validators.adb:2166 invalid data for my own schema but I am getting same error for this schema.

<?xml version="1.0"?>

<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">

<xs:element name="note">
  <xs:complexType>
    <xs:sequence>
      <xs:element name="to" type="xs:string"/>
      <xs:element name="from" type="xs:string"/>
      <xs:element name="heading" type="xs:string"/>
      <xs:element name="body" type="xs:string"/>
    </xs:sequence>
  </xs:complexType>
</xs:element>

</xs:schema>

Changing the version and scheam tag to 
<?xml version="1.0" encoding="UTF-8"?>

<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
elementFormDefault="qualified"
targetNamespace="http://example.com/schemas/agent"
xmlns:agent="http://example.com/schemas/agent"> 

does not make any difference. I tried looking into schema-validators.adb but that was of no use. Please help.