XSD: How do schemas point out errors?

[singularis]

I have edited simple.xml slightly and added another element (called "bad") that should result in the document being invalid. Yet the schema does not pick up on this.

I was using Internet Explorer 7 to read the xml file. Any help would be good

Contents of Simple.xsd (the schema):

<?xml version = "1.0" encoding = "UTF-8"?>
<!--Generated by XML Authority. Conforms to w3c http://www.w3.org/2001/XMLSchema-->
<xsd:schema xmlns:xsd = "http://www.w3.org/2001/XMLSchema">
	<xsd:element name = "vehicles">
		<xsd:complexType>
			<xsd:sequence>
				<xsd:element name = "nickname" type = "xsd:string" maxOccurs = "unbounded"/>
			</xsd:sequence>
		</xsd:complexType>
	</xsd:element>
</xsd:schema>