one upload per file control. javascript can dynamically add more file
controls, or a common technique is show list of uploaded files and have
the button add to the list (see web mail programs handling of attachments).

-- bruce (sqlwork.com)

Nope. Have multiple <input type="file"...> for multi-file upload..

Hint:

You'll always need to have one element per file to be uploaded.
But you don't need to display all those file elements.

http://the-stickman.com/web-development/javascript/upload-multiple-files-with-a-
single-file-element/