Forum:CHAT HELP

I saw something cool on the iCarly Wiki, and would like to know how to do it. When you enter the wikia chat, it doesn't say "~ has joined the chat~"... instead, it says "~ has entered the Shay apartment~". I know there most be some kind of javascript involved here, and if not, a MediaWiki page. Can someone explain how to achieve this? Thanks!! :) Ab  by  &bull; 1/29/12 20:10 (UTC) 20:10, January 29, 2012 (UTC)
 * Configure, MediaWiki:Chat-user-joined to achieve this.  Plasma  ( Talk )  @Community Central   20:16, January 29, 2012 (UTC)