Ajax add on to file field to check file size

I have this page with file fields. I need to have ajax script implemented so that when a user select a file, there is a rotation image shown at the right hand side of the field, then indicate whether the file size is ok or over the limit. If okay, it will display a tick, if not it will display oversize warning. The ajax actually pass the $_FILE['tmp_name']['size'] to a php file, which checks if the file size is over the limt and pass back. Once receiving the returned value, the ajax will actually determine whether the submit button is clickable. If any of the file fields have warning, the submit button is not clickable. ## Deliverables 1) Complete and fully-functional working program(s) in executable form as well as complete source code of all work done. 2) Deliverables must be in ready-to-run condition, as follows (depending on the nature of the deliverables): a) For web sites or other server-side deliverables intended to only ever exist in one place in the Buyer's environment--Deliverables must be installed by the Seller in ready-to-run condition in the Buyer's environment. b) For all others including desktop software or software the buyer intends to distribute: A software installation package that will install the software in ready-to-run condition on the platform(s) specified in this bid request. 3) All deliverables will be considered "work made for hire" under U.S. Copyright law. Buyer will receive exclusive and complete copyrights to all work purchased. (No GPL, GNU, 3rd party components, etc. unless all copyright ramifications are explained AND AGREED TO by the buyer on the site per the coder's Seller Legal Agreement). ## Platform JavaScript, AJAX