/agile_uploader

Upload files, other form data, and optionally resize any uploaded images on the client side before uploading to save on server bandwidth. Resizing before uploading can also help save a server from processing unnecessarily large image files if further image processing (manipulation or simply having the server save multiple sizes) is done on the server.

Primary LanguageActionScript

Please see the "bin" directory for complete examples and all
non-flash source code and supporting files for using Agile Uploader.

You do not need to use any of these files if you wish to build
your own JavaScript that uses Flash's ExternalInterface to work
with the methods within the compiled SWF. You could then use
the agile-uploader-3.0.js file as a reference. Note that this
file uses jQuery, but you need not use jQuery if so desired.

You can also refer to the Agile Uploader project page: 
http://www.shift8creative.com/projects/agile-uploader/index.html