I have a form

f = appuifw.Form(data, 17)
f.execute()
self.get_stuff_from_form(f)
...

def get_stuff_from_form(self, form):

a = int(form[2][2][1])
b = int(form[0][2])
if (<the form was cancelled>):
...


How can I tell if my form was cancelled or not? Is it one of the attibutes of 'form'?

Thanks