Backend webpage updates

I am a graphic/web designer with a limited knowledge of php. I need somone to develop code that allows my clients to update/change pre defined text areas within individual web pages. They need to do this through a (password protected) web page interface so that they can view the original text and then update or change it. There should be a facility to limit the amount of text. Idealy this should be a package that I can apply to any of my clients websites with instructions on what variables apply and how I change them for the relevant site/page. I am currently designing a site with 22 individual pages that need the above facility with seperate usernames & passwords for each page. ## Deliverables 1) Complete and fully-functional working program(s) in executable form as well as complete source code of all work done. 2) Installation package that will install the software (in ready-to-run condition) on the platform(s) specified in this bid request. 3) Exclusive and complete copyrights to all work purchased. (No GPL, 3rd party components, etc. unless all copyright ramifications are explained AND AGREED TO by the buyer on the site). ## Platform all current web browsers