[xsd] Il validatore mi dà errore

[Stemby]

Buonasera,
qualcuno sa spiegarmi perché il validatore mi dà il seguente errore?

Validation stopped at line 5, column 85: Invalid child 'element' in the complex type

test.xml:

<?xml version="1.0" encoding="UTF-8"?>
<transcript xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="universitas.xsd">
  <exam title="Test">
    <credits>3</credits>
    <date>2008-09-15</date>
    <mark>30</mark>
  </exam>
</transcript>

universitas.xsd:

<?xml version="1.0" encoding="UTF-8"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">
  <xs:element name="transcript">
    <xs:complexType>
      <xs:element name="exam" type="examType" minOccurs="0" maxOccurs="unbounded" />
      <xs:attribute name="title" type="xs:string" use="required" />
    </xs:complexType>
  </xs:element>
  <xs:complexType name="examType">
    <xs:sequence>
      <xs:element name="credits" type="xs:integer" />
      <xs:element name="date" type="xs:date" />
      <xs:element name="mark" type="xs:integer" />
    </xs:sequence>
  </xs:complexType>
</xs:schema>

Grazie!