Add javascript to Form onSubmit event

[Pablo Ruggia]

Hi !
I want to execute a javascript function before my form is submited. All i've
found is using is to use something like this:
f.addEventHandler(FormEventType.SUBMIT, "myjsfunction")
But this is deprecated, what is the recommended way of doing this ? I'm
using Tapestry 4.0.2
Thanks !