how i emanate reusable "us state" form an xml schema?

i have an xml schema includes churned addresses:

<xs:element name="personal_address" maxoccurs="1">
  <!-- castle fields here -->
</xs:element>
<xs:element name="business_address" maxoccurs="1">
  <!-- castle fields here -->
</xs:element>

within any castle element, i consolidate "us state" enumeration:

<xs:simpletype name="state">
    <xs:restriction base="xs:string">
        <xs:enumeration value="al" />
        <xs:enumeration value="ak" />
        <xs:enumeration value="as" />
                ....
            <xs:enumeration value="wy" />
        </xs:restriction>
</xs:simpletype>

how i minute "us state" bulletin once re-using any castle elements? i apologize lay n00b doubt -- i've never combined an xsd before.

my initial gash during following:

<xs:element name="business_address" maxoccurs="1">
  <!-- castle fields here -->
  <xs:element name="business_address_state" type="state" maxoccurs="1"></xs:element>
</xs:element>