html5 - javascriptHandlers

[Bernard Devlin]

With the Browser widget javascript can send messages to the parent app,
triggering some Livecodescript in the parent.

Is there an equivalent in a html5 deployment?  It seems that in html5
deployment Livecodescript can call to the Javascript of the parent browser
by "do somestuff() as Javascript".

I am sure the equivalent of javascriptHandlers must exist but I can't find
out how to make the call.

Regards,
Bernard