Uploading Multiple Files

I have a page with only one <input type=file ..> tag.

The page submits to itself with a "Save File to List" button. User browses thru the files and click the above button to add the file to a list. In the end user clicks "Submit" to upload all the files from the list to the server.

Problem # 1

I'm not sure how to save FILE type object collection/array, with every click of first button.

Problem # 2

How do I post that collection/array varaible when submit (2nd button) is clicked.