[Mediawiki-l] How to change "Main Page" displayed on home page?

[Tim Ware]

 > Just change this page in your wiki:
 > MediaWiki:Mainpage
 > [[MediaWiki:Mainpage]]
 >

If I go to:

MediaWiki:Mainpage

and click "edit", I just see

Main Page

If I change that text, then the system wants to look for a page with  
the next text as the main page.

Please remember, I don't want to change the URL of the main page,  
just the displayed text "Main Page".

Tim