title: Download textarea contents as a file using only Javascript (no server-side)
body: <p>I am being asked to make a "download" button that downloads the contents of a textarea on the same page as a file, with the browser's "Save As..." dialog showing up. Copy/paste would do the job just fine, but it is a "requirement".</p>
  
  <p>Right now, I am just posting the contents of the textarea to the server, which echos them back with <code>Content-disposition: attachment</code> slapped on. Is there a way to do this with just client-side Javascript? </p>