Forum:Scrolling feed

How do I add a scrolling news feed to my wiki? I have the html code but the wiki doesn't accept it. Is there a html editor?
 * I guess it would be possible with JavaScipt.  Manyman  (Talk)  06:05, July 10, 2010 (UTC)
 * Like the one featured on the main page of Wikiality. Just look at the page sources and MediaWiki:Common.js. fingernails 10:09, July 10, 2010 (UTC)