Composer HTML source shortcut

[sime]

There needs to be a shortcut for viewing HTML Source. I dont mind 
putting in a bug report, but stumped on which shortcut to use. First one 
into my mind was Control+H. 'H' for 'HTML Source'

Listing of current shortcuts:
http://www.mozilla.org/docs/end-user/moz_shortcuts.html#composer
-sime