Browsers are notorious at hanging on tenaciously to cached pages. This problem is evident in Ajax applications when sending XMLHTTPRequest GET requests to Internet Explorer. Even when you use all manner of fancy headers like "Pragma: no-cache" or "Cache-Control: must-revalidate" you'll often find that you receive a cached page rather than a 'live' one. Here's something else you can try, which has worked well for me, and essentially only needs one line of Javascript.
Create the script once and reference in any number of ways. The example goes into Date Stamps, News, Quotes, etc. One file to update and one line to include in the HTML page.
You can use this as a fake Server-Side Includes to create site navigation. You update the one .js file to alter navigation.
A random number is useful- if not required- in the creation of many popular JS applications, such as a dice, random image script, or random link generator. Learn how to generate a random number in JavaScript.