title: Iframe Fallback Message
body: <p>I am displaying a locally hosted PDF in an iframe. Most people see the PDF embedded on the page, but there are a few configurations where the user is prompted to download the PDF, leaving a large blank spot where the PDF would be.</p>
  
  <p>I would like to display some kind of a fallback message in those cases but have not been able to find any information regarding fallback for an iframe. I would prefer to avoid javascript but would use it if no other option is available.</p>
  
  <p>My iframe code is <code>&lt;iframe src="PDF-link-here" width="100%" height="800px" marginheight="0" frameborder="0""&gt;&lt;/iframe&gt;</code></p>