1<?xml version="1.0"?>
2<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema">
3  <xsd:complexType name="PurchaseOrderType">
4    <xsd:sequence>
5      <xsd:all>
6        <xsd:element name="shipTo" type="USAddress"/>
7        <xsd:element name="billTo" type="USAddress"/>
8        <xsd:element name="items" type="Items"/>
9      </xsd:all>
10      <xsd:sequence>
11        <xsd:element ref="comment" minOccurs="0" maxOccurs="unbounded"/>
12      </xsd:sequence>
13    </xsd:sequence>
14    <xsd:attribute name="orderDate" type="xsd:date"/>
15  </xsd:complexType>
16</xsd:schema>
17