title: Forcing cache expiration from a JavaScript file
body: <p>I have an old version of a JS file cached on users' browsers, with expiration set to 10 years (since then, I have learned how to set expires headers correctly on my web server). I have made updates to the JS file, and I want my users to benefit from them.</p>
  
  <ul>
  <li>Is there any way my web server can force users' browsers to clear the cache for this one file, short of serving a differently named JS file?</li>
  <li>In the future, if expires headers are not set correctly (paranoia), can my JS file automatically expire itself and force a reload after, say, a day has passed since it was cached?</li>
  </ul>
  
  <p>EDIT: Ideally I want to solve this problem <em>without</em> changing HTML markup on the page that hosts the script.</p>