title: HTTP form submit callback
body: <p>I'm posting a form that causes a file to be downloaded. So my browser page does not change. My form is e.g. <code>form action="/download/file.txt"</code>. I'm aware that I could use JQuery and download the file with AJAX and use the JQuery callback mechanisms. However, I don't want to use JQuery because this is a learning experience. Is there any way to call a Javascript function when my file has downloaded?</p>