title: Using nillable elements in BizTalk expressions
body: <p>I have nillable decimal element defined in xsd schema like this:</p>
  
  <pre><code>&lt;xs:element name="myDecimalValue" nillable="true" type="xs:decimal" /&gt; 
  </code></pre>
  
  <p>This is distinguished field and I want to check if it is nill in expression shape. I could use xpath() function like this:</p>
  
  <pre><code>xpath("string(//*[local-name()='myDecimalValue']/@*[local-name()='nil'])") == "true"
  </code></pre>
  
  <p>But it looks a little bit complicated for simple null-checking. So I'm wondering if I'm missing something and there is better way to do it?</p>