function getScreen(url, size) { if (url === null) { return ""; } size = (size === null) ? "big" : size; var vid; var results; results = url.match("[\\?&]v=([^&#]*)"); vid = (results === null) ? url : results[1]; if (size == "small") { return "http://img.youtube.com/vi/" + vid + "/2.jpg"; } else { return "http://img.youtube.com/vi/" + vid + "/0.jpg"; } }