[TYPO3-english] how to : get my plugin to appear in the Selected Plugin box on the Edit Page Content page

[Calgacus map Brude]

Hi,
I am just making my first  little extbase extension and it seems ok so far but after I installed the extension and I try to add it to a page I find that it does not appear in  the Selected Plugin box on the Edit Page Content page, so I cannot use it on a page.  What did I miss?   
My extension is just a tiny little test thing, it does nothing but display a message from a database.
I am using typo3 v 4.5.3 with extbase.

Thanks!