title: labwindows nullChk returns with an error
body: <p>What is nullChk and how should it be properly used?</p>
  
  <p>I am using the following line of code:</p>
  
  <pre><code>nullChk(temp = malloc (numBytes + 1));  
  </code></pre>
  
  <p>and I get the following error message:</p>
  
  <pre><code>  700, 9    error: use of undeclared identifier 'error'
    700, 9    error: use of undeclared label 'Error'
  </code></pre>