Document Control/backup System

Requirement: a web based application, to backup documents based on preconditions. 1. User authentication to login to the application. 2. every user has restrictions of generic and supervisor previlages. 3. user creation requirements for administrator previlages. 4. every user to have, a option to upload his file(workfile) to the server, reveiw any previously uploaded files, 5. the file storage hierarchy is based on a predefined format. so the file uploaded by the user is supposed to be copied to the folder as per the requirement 6. user to have option to change the state of the uploaded file to: to be reviewed. final. IN progress (Default) 7. once a user(non supervior) changes the state of a particular file from in progress to any other state, he will not be able to download that file again! 8. superviors will have the option to access any file in any state that he uploads. 9. administrator should have option to view/ modify / change all the files uploaded by all the users... 10. no need for versioned file hierachy, any file already uploaded, should be overwritten if already exists for that user...