The DOMContentLoaded event fires when parsing of the current page is complete; the
load event fires when all files have finished loading from all resources, including
ads and images. DOMContentLoaded is a great event to use to hookup UI functionality
to complex web pages.
When each event fires, the word "DONE!" is printed to the screen. To try the test
again, press Ctrl+F5 (to refresh this page without using cached images).