I think this is JavaScript code i need.

I am making a prediction web site it works on the basis that a person picks a number from a number grid and that takes them to the relevant numbers page.This page shows the prediction in text.

what i would like to do is have the prediction text change after say 48hours automatically to another different prediction text but on the same page and relevant to the same number ..so one day a person picks say .. number 1 and they get the word "hello"then they click on number one again 48hours later and get the word "goodbye". so the text is constantly changing every 48hours to something completely new.

please help i am a JavaScript rookie.