title: How to learn why an HTML element is disabled
body: <p>I'm trying to use an open source HTML5 file uploader snippet in one of my pages, and have put (I believe) all the correct javascript in place.  </p>
  
  <p>However, when the page loads I see the 'choose file..' button along with the text box that shows the path to the file on my hard drive, and they're both greyed out.</p>
  
  <p>In looking through the Google and FireFox development tools I can't see why this would be; the CSS involved is quite involved and I can't tell easily whether there's a block display of hidden in there, or whether something else is disabled.  </p>
  
  <p>Nothing's jumping out.  Are there HTML or CSS inspectors that can help figure out why HTML element X is disabled?</p>