'Add a back button with a given title, the tab-next button,
its name in the Control table, possibly initially disabled.
Return the button, so that events can be associated'

def back(self, title, next, name='Back', active=1):

    if active:
        flags = 3
    else:
        flags = 1
    return self.pushbutton(name, 180, (self.h - 27), 56, 17, flags, title, next)
