title: How to allow negative values, xml schema?
body: <pre><code>&lt;xs:element name="Quantity" minOccurs="1"&gt;
   &lt;xs:simpleType&gt;
   &lt;xs:restriction base="xs:string"&gt;
    &lt;xs:maxLength value="10" /&gt; 
    &lt;xs:minLength value="1" /&gt; 
    &lt;xs:pattern value="[0-9]*" /&gt; 
    &lt;/xs:restriction&gt;
    &lt;/xs:simpleType&gt;
    &lt;/xs:element&gt;
  </code></pre>