Problem with a W3C XML Schema

I have written this W3C XML Schema for Orders

<xsd:schema
xmlns:xsd="http://www.w3.org/2001/XMLSchema"
xmlns:stns="java:examples.newTypes"
attributeFormDefault="qualified"
elementFormDefault="qualified"
targetNamespace="java:examples.newTypes">
	<xsd:complexType name="xorder">
		<xsd:element name="xorderID" type="xsd:string"
nillable="true">
	</xsd:element>
		<xsd:element name="xorderDate" type="xsd:dateTime"
nillable="true">
	</xsd:element>
		<xsd:element name="xrequest" type="requesttype"/>
		<xsd:sequence>
			<xsd:element name="xproduct" type="producttype"
minOccurs="0" maxOccurs="unbounded"/>
		</xsd:sequence>
	</xsd:complexType>
	<xsd:complexType name="requesttype">
		<xsd:element name="xrequestID" type="xsd:string"/>
		<xsd:element name="xrequester" type="xsd:int"/>
	</xsd:complexType>
	<xsd:complexType name="producttype">
		<xsd:element name="xproductID" type="xsd:string"/>
		<xsd:element name="xproductName" type="xsd:string"/>
		<xsd:element name="xproductPrice" type="xsd:float"/>
	</xsd:complexType>
</xsd:schema>

I am getting error at this line
<xsd:element name="xorderID" type="xsd:string"
nillable="true">

The Schema does'nt appear to be valid. Invalid element
xsd:element at this position.

What could be the problem? And how to correct it?

Regards,
Mukul


		
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