trigger onload event when downloading a file in an iframe

<script>
 function download(){
    var url = 'http://example.com/dload.py';
    var htm = '<iframe src="' + url +'" onload="downloadComplete()"></iframe>';
    document.getElementById('frameDiv').innerHTML = htm;
 }
</script>

<div style="display:none" id="frameDiv">
</div>
<button onclick="download()">download file</button>

출처 : http://stackoverflow.com/questions/1524639/how-to-trigger-onload-event-when-downloading-a-file-in-an-iframe