purchaseOrderChanges.xsd

<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
            xmlns:tns="http://tempuri.org/PurchaseOrderSchema.xs"
            targetNamespace="http://tempuri.org/PurchaseOrderSchema.xs"
            elementFormDefault="qualified">
    <xs:element name="PurchaseOrder" type="PurchaseOrderType"/>
    <xs:complexType name="PurchaseOrderType">
        <xs:all>
            <xs:element name="ShipTo" type="USAddress" maxOccurs="2"/>
            <xs:element name="BillTo" type="USAddress"/>
        </xs:all>
        <xs:attribute name="OrderDate" type="xs:date"/>
    </xs:complexType>

    <xs:complexType name="USAddress">
        <xs:sequence>
            <xs:element name="name"   type="xs:string"/>
            <xs:element name="street" type="xs:string"/>
            <xs:element name="city"   type="xs:string"/>
            <xs:element name="state"  type="xs:string"/>
            <xs:element name="zip"    type="xs:integer"/>
        </xs:sequence>
        <xs:attribute name="country" type="xs:NMTOKEN" fixed="US"/>
    </xs:complexType>
</xs:schema>