open / save feature for web application

I need someone to develop a simple open / save web application. You start with a page with an open and a save button, and with a js that contains a variable filevar="sdfsdafgsvnbdfvgbfdsmngvmdfngfdgdfgdfxcvb" If the user clicks save, the application should push a file to be saved with filevar as a content (as a txt file). If the user clicks open, the application should allow the user to browse local files and chose a txt, then upload the txt, read it, and put the content in filevar. This app will work in a linux server with php and apache. It should work on all browsers. And it should allow multiple users. If you use libraries they should allow commercial applications. If you are interested post your bid along with the technology to be used (php, ajax, js)