title: How to retrieve and alert JSON.stringify
body: <p>Im trying to alert a user that the file size is not allowed and the size of the image.</p>
  
  <p>in  my code I'm doing:</p>
  
  <pre><code>alert('Error' + [JSON.stringify(err)]);
  </code></pre>
  
  <p>The alert message returns:</p>
  
  <pre><code>Error[{"message":"File size not allowed","error":"FILE_SIZE","param":10722753}]
  </code></pre>
  
  <p>I would like the alert to say:</p>
  
  <pre><code>File size not allowed 10722753
  </code></pre>
  
  <p>How can I clean up this error message and get the details our of the err object?</p>