If you want to upload a video from your computer, use the Audio-Video Mandala tool instead of Visuals. You can use Visuals for videos already online, on YouTube or Vimeo.
To get the id code for a video, open your video in either YouTube or Vimeo, then look at the URL in your address bar.
Find the YouTube id after the equal sign in the video's URL. For example, the URL
http://www.youtube.com/watch?v=zDZFcDGpL4U |
corresponds to the id code
zDZFcDGpL4U |
The Vimeo id follows the slash after "vimeo.com". For example, the URL
http://vimeo.com/30581015 |
corresponds to the id code
30581015 |