title: How to get the maximum of a calculated value in XQuery?
body: <p>I have many orders like the following:</p>
  
  <pre><code>&lt;order id="1"&gt;
     &lt;TargetPrice&gt;100&lt;/TargetPrice&gt;
     &lt;Qty&gt;2&lt;/Qty&gt;
  &lt;/order&gt;
  </code></pre>
  
  <p>I need an Xquery to get the order with highest value (where value is TargetPrice*Qty)</p>
  
  <p>How can i do that?</p>