title: Stop JavaScript script execution
body: <p>I have a form which is being submitted by ajax.  Before submission, there's a function which checks if a textarea in the form is empty before submitting.  if it is empty, I need to stop the script and show a modal box AND prevent the submission of data to proceed.</p>
  
  <p>How do I stop execution?  Do I use </p>
  
  <pre><code>break;
  </code></pre>
  
  <p>?</p>