I'm using this javascript code, per Mozilla docs, but it's not
working in Mozilla, just in Chrome and Opera (don't know if it's
working in ie 10--FormData is supposedly supported in IE version
10--but I'm only really concerned about Firefox).  var data =
new FormData(document.getElementById("uploadform"));
var selected_file = document.getElementById('file').files[0];
data.append('file-0', selected_file); firefox also causes server
error on the ajax file upload:  [Wed Jun 05 21:34:53 2013]
[error] [client ::1] PHP Notice:  Undefined index: file-0 in
/home/jeff/public/website.com/public/upload.php on line 11,
referer: http://localhost/ I have no idea why "files" does not
seem to be working. I've posted on Mozilla support forum with no
answers, and on stack overflow with one attempted answer. Here's
the relevant Mozilla docs page: Using FormData Objects.  I've
tested firefox 21, 24 nightly, and 10 on a linux machine, and
tested firefox 21 on a windows machine, all with the same
results.