Hi all (well, this time it should be Hi Erel..),
I opened an old B4J program and noted the existence of a button_action sub. No surprise, this is also as it is documented.
Then I added a new button by the Designer and among the listed events (both right-clicking it and by tools/generate members option) there was no more Action but Click, so the generated code led to button1_click this time.
Both forms work. I wrote this message only to drive Erel's attention to a marginal point in order to update the documentation or to eventually modify the compiler so to it could automatically translate from previous form to the newer one or whatever he finds more appropriate.