javascript & smil question

Hi everyone, I've got a quick question that I can't seem to find an answer to.  Does anyone know about the ability of  including javascript in smil?  I've got a project I'm working on that has a live stream, and I'd like to be able to put 3 feature .rm clips underneath that stream in the layout.  I was wondering if it's possible to use js to make smil smart enough to know that if a user clicked on one of the three features and another was playing, that it would stop playing the first feature and play the one clicked on.  Any help would be appreciated.  

For reference this is the scheme of the layout:
__________________
|          stream          |
|                              |
 | feature1     2      3   |
|                              |
| ________________ |

Thanks in advance,
Kevin