Changes

Where sample.vtt is an external WEBVTT WebVTT file marked up like so:

If you feel like some self-punishment you can check out more about how it works by reading the [http://dev.w3.org/html5/webvtt/ WEBVTT WebVTT spec] as well as the [http://www.whatwg.org/specs/web-apps/current-work/multipage/the-video-element.html#the-track-element HTML5 Track Element spec].