title: Is it possible to catch browser's File Open/Save dialog event using Javascript
body: <p>Using Javascript is it possible to listen for browser's file open/save dialog box event. I want to perform an action when I am notified that the save file dialog box has opened now. Specifically I want to hide a loading spinner when dialog box opens (but this could very well be any other action )</p>
  
  <p>I believe I can do that for a dialog box that I create, not sure if it can be done for the browser's standard dialog box.</p>
  
  <p>Any pointers for that would be really helpful.</p>