Track when a download file dialog appears
<p>I have some links that when the user clicks one, it links to a php script which runs some stored procedures to generate data and then calls another script to download the data as an excel spreadsheet.  This all works fine.</p>

<p>What I'd like to do is have a loader gif appear beside the link that was clicked clicked and when the dialog appears to get the user to save the file, have that gif disappear again.</p>

<p>Can I track this event at all to achieve this?  Not had much luck so far.</p>
