I am developing a page (one-time use - its registration page) when a visitor opens dialog box and uploads files throught input type file multiple. All worked fine, but my client
Note on the "classic form"/JQuery solution given by Gregoire: this will not work on the newly added inputs, as the listener is not active on them. If you modify this to use delegated events you have a working clean solution:
$("#files").on("change", "input", function(event){
$('#files').append('')
});