Display random text file on page, but same file if they refresh.

I'd like a script written that can do the following; It should display the contents of a random text file in a scrollable text box on a webpage. The contents of the text box must be selectable so the user can copy (but not edit) it's contents. The random text files will be stored in a folder. There will be a changing number of text files in the folder, so I would like the script to check what files are in the folder and display one at random. Each visitor should see the contents of the random file when they first visit, but if they then refresh the page, I want the same file to be displayed to them, not a different file. (I want the maximum period to be 24 hours, then if they come back they can see a different file.) Somewhere on the webpage it should also display the file name of the text file displayed. Please add the word 'January' to your bid, otherwise I'll ignore it. Thanks