window.applicationCache.addEventListener('updateready', function(e) {
  if (window.applicationCache.status == window.applicationCache.UPDATEREADY) {
    window.applicationCache.swapCache();
    if (confirm('A new version of this site is available. Load it?')) {
      window.location.reload();
    }
  }
}, false);

CACHE MANIFEST
# version 1.0.0

CACHE:
/html5/src/logic.js
/html5/src/style.css
/html5/src/background.png

NETWORK:
*

Turn off your internet connection and refresh this page!