[Mediawiki-l] Adding a "strikeout" button to the text editing format toolbar

[Monahon, Peter B.]

I'd love to add a "strikeout text" button to the text editing format
toolbar.  I found this:

http://www.mediawiki.org/wiki/User:Robchurch/Extra_toolbar_buttons (see
below *)

(And this: http://commons.wikimedia.org/wiki/Mediawiki_edit_toolbar )

But can't see how to implement it - does it require an extension, or
where would the code go, or is it experimental and non-functional?

Any clues to this or other solutions?

Help?  Thanks.

===

* Quoted from above:

....[snip]...
function addCustomButton(imageFile, speedTip, tagOpen, tagClose,
sampleText, imageId) {
   mwCustomEditButtons[mwCustomEditButtons.length] =
    {"imageId": imageId,
     "imageFile": imageFile,
     "speedTip": speedTip,
     "tagOpen": tagOpen,
     "tagClose": tagClose,
     "sampleText": sampleText};
}
....[snip]...
addCustomButton('http://upload.wikimedia.org/wikipedia/commons/c/c9/Butt
on_strike.png','Rayer','<s>','</s>','');
....[snip]... 
/*