JavaScript file not updating no matter what I do

Question

I have an external JavaScript file and whether in FireFox or Chrome, whether all browsing data is cleared, it will NOT update no matter what. I believe something happen

Answer 1

How about adding a '?2' to the tag?

The server should return the same file with or without the '?2', but the browser should see it as a different file and redownload. You can just change this query string whenever the file is changed.

adapted from: http://blog.httpwatch.com/2007/12/10/two-simple-rules-for-http-caching/