This is how the book has the files (3 of them) but xml notepad says shipTo 
has to be filled out, I hate it when book examples do not work :(


======== INVOICE.XML ==========

<?xml version="1.0" encoding="UTF-8"?>
<invoice:invoice xmlns:invoice="http://www.skatestown.com/ns/invoice"
   xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
   xsi:schemaLocation="http://www.skatestown.com/ns/invoice
                       ./invoice.xsd"
   id="43871" submitted="2004-01-05" customerId="73852">
   <billTo id="addr-1">
      <company>The Skateboard Warehouse</company>
      <street>One Warehouse Park</street>
      <street>Building 17</street>
      <city>Boston</city>
      <state>MA</state>
      <postalCode>01775</postalCode>
   </billTo>
   <shipTo href="addr-1"/>
   <order>
      <item sku="318-BP" quantity="5" unitPrice="49.95">
         <description>Skateboard backpack; five pockets</description>
      </item>
      <item sku="947-TI" quantity="12" unitPrice="129.00">
         <description>Street-style titanium skateboard.</description>
      </item>
      <item sku="008-PR" quantity="1000" unitPrice="0.00">
         <description>Promotional: SkatesTown stickers</description>
      </item>
   </order>
   <tax>89.89</tax>
   <shippingAndHandling>200</shippingAndHandling>
   <totalCost>2087.64</totalCost>
</invoice:invoice>



======== INVOICE.XSD ==========

<?xml version="1.0" encoding="UTF-8" ?>
<xsd:schema
    targetNamespace="http://www.skatestown.com/ns/invoice"
    xmlns:po="http://www.skatestown.com/ns/po"
    xmlns:xsd="http://www.w3.org/2001/XMLSchema"
    xmlns="http://www.skatestown.com/ns/invoice">

 <xsd:import namespace="http://www.skatestown.com/ns/po" 
schemaLocation="./po.xsd" />
 <xsd:annotation>
  <xsd:documentation xml:lang="en">
         Invoice schema for SkatesTown.
  </xsd:documentation>
 </xsd:annotation>
 <xsd:element name="invoice" type="invoiceType" />
 <xsd:complexType name="invoiceType">
  <xsd:sequence>
   <xsd:element name="billTo" type="po:addressType" />
   <xsd:element name="shipTo" type="po:addressType" />
   <xsd:element name="order">
    <xsd:complexType>
     <xsd:sequence>
      <xsd:element name="item" type="itemType" maxOccurs="unbounded" />
     </xsd:sequence>
    </xsd:complexType>
   </xsd:element>
   <xsd:element name="tax" type="priceType" />
   <xsd:element name="shippingAndHandling" type="priceType" />
   <xsd:element name="totalCost" type="priceType" />
  </xsd:sequence>
  <xsd:attribute name="id" type="xsd:positiveInteger" use="required" />
  <xsd:attribute name="submitted" type="xsd:date" use="required" />
  <xsd:attribute name="customerId" type="xsd:positiveInteger" use="required" 
/>
 </xsd:complexType>
 <xsd:complexType name="itemType">
  <xsd:complexContent>
   <xsd:extension base="po:itemType">
    <xsd:attribute name="unitPrice" type="priceType" use="required" />
   </xsd:extension>
  </xsd:complexContent>
 </xsd:complexType>
 <xsd:simpleType name="priceType">
  <xsd:restriction base="xsd:decimal">
   <xsd:minInclusive value="0" />
  </xsd:restriction>
 </xsd:simpleType>
</xsd:schema>


========== PO.XSD =========

<?xml version="1.0" encoding="UTF-8" ?>
<xsd:schema xmlns="http://www.skatestown.com/ns/po" 
targetNamespace="http://www.skatestown.com/ns/po" 
xmlns:xsd="http://www.w3.org/2001/XMLSchema">
 <xsd:annotation>
  <xsd:documentation xml:lang="en">
   Purchase order schema for SkatesTown.
  </xsd:documentation>
 </xsd:annotation>
 <xsd:element name="po" type="poType" />
 <xsd:complexType name="poType">
  <xsd:sequence>
   <xsd:element name="billTo" type="addressType" />
   <xsd:element name="shipTo" type="addressType" />
   <xsd:element name="order">
    <xsd:complexType>
     <xsd:sequence>
      <xsd:element name="item" type="itemType" maxOccurs="unbounded" />
     </xsd:sequence>
    </xsd:complexType>
   </xsd:element>
  </xsd:sequence>
  <xsd:attribute name="id" use="required" type="xsd:positiveInteger" />
  <xsd:attribute name="submitted" use="required" type="xsd:date" />
  <xsd:attribute name="customerId" use="required" type="xsd:positiveInteger" 
/>
 </xsd:complexType>
 <xsd:complexType name="addressType">
  <xsd:sequence>
   <xsd:element name="name" type="xsd:string" minOccurs="0" />
   <xsd:element name="company" type="xsd:string" minOccurs="0" />
   <xsd:element name="street" type="xsd:string" maxOccurs="unbounded" />
   <xsd:element name="city" type="xsd:string" />
   <xsd:element name="state" type="xsd:string" minOccurs="0" />
   <xsd:element name="postalCode" type="xsd:string" minOccurs="0" />
   <xsd:element name="country" type="xsd:string" minOccurs="0" />
  </xsd:sequence>
  <xsd:attribute name="id" type="xsd:ID" />
  <xsd:attribute name="href" type="xsd:IDREF" />
 </xsd:complexType>
 <xsd:complexType name="itemType">
  <xsd:sequence>
   <xsd:element name="description" type="xsd:string" minOccurs="0" />
  </xsd:sequence>
  <xsd:attribute name="sku" use="required">
   <xsd:simpleType>
    <xsd:restriction base="xsd:string">
     <xsd:pattern value="\d{3}-[A-Z]{2}" />
    </xsd:restriction>
   </xsd:simpleType>
  </xsd:attribute>
  <xsd:attribute name="quantity" use="required" type="xsd:positiveInteger" 
/>
 </xsd:complexType>
</xsd:schema>