xmlns:po="http://www.example.com/PO1"

	    targetNamespace="http://www.example.com/PO1"

	    elementFormDefault="unqualified"

	    attributeFormDefault="unqualified">

  <xsd:annotation>

    <xsd:documentation xml:lang="en">

Purchase order schema for Example.com.

   Copyright 2000 Example.com. All rights reserved.

    </xsd:documentation>

  </xsd:annotation>

  <xsd:element name="purchaseOrder" type="po:PurchaseOrderType"/>

  <xsd:element name="comment" type="xsd:string"/>

  <xsd:complexType name="PurchaseOrderType">

    <xsd:sequence>

      <xsd:element name="shipTo" type="po:USAddress"/>

      <xsd:element name="billTo" type="po:USAddress"/>

      <xsd:element ref="po:comment" minOccurs="0"/>

      <xsd:element name="items" type="po:Items"/>

    </xsd:sequence>

    <xsd:attribute name="orderDate" type="xsd:date"/>

  </xsd:complexType>

  <xsd:complexType name="USAddress">

    <xsd:sequence>

      <xsd:element name="name" type="xsd:string"/>

      <xsd:element name="street" type="xsd:string"/>

      <xsd:element name="city" type="xsd:string"/>

      <xsd:element name="state" type="xsd:string"/>

      <xsd:element name="zip" type="xsd:decimal"/>

    </xsd:sequence>

    <xsd:attribute name="country" type="xsd:NMTOKEN" fixed="US"/>

  </xsd:complexType>

  <xsd:complexType name="Items">

    <xsd:sequence>

      <xsd:element name="item" minOccurs="0" maxOccurs="unbounded">

        <xsd:complexType>

          <xsd:sequence>

            <xsd:element name="productName" type="xsd:string"/>

            <xsd:element name="quantity">

              <xsd:simpleType>

                <xsd:restriction base="xsd:positiveInteger">

                  <xsd:maxExclusive value="100"/>

                </xsd:restriction>

              </xsd:simpleType>

            </xsd:element>

            <xsd:element name="USPrice" type="xsd:decimal"/>

            <xsd:element ref="po:comment" minOccurs="0"/>

            <xsd:element name="shipDate" type="xsd:date" minOccurs="0"/>

          </xsd:sequence>

          <xsd:attribute name="partNum" type="po:SKU" use="required"/>

        </xsd:complexType>

      </xsd:element>

    </xsd:sequence>

  </xsd:complexType>

  <xsd:simpleType name="SKU">

    <xsd:restriction base="xsd:string">

      <xsd:pattern value="\d{3}-[A-Z]{2}"/>

    </xsd:restriction>

  </xsd:simpleType>

</xsd:schema>