how to resize mega widgets

[student]

sorry if this is somewhere in the docs .. .but i just can't find it

i'm creating a Pmw.TextDialog and i can figure out how to change the
default size of the text window inside, i create it as follows:

self.dialog = Pmw.TextDialog(parent, scrolledtext_labelpos = 'n',
                             title = title,
                             defaultbutton = 0,
                             label_text = label,
                             hull_width = 100,
                             hull_height = 150)

these options don't seem to do anything (hull_width and hull_height),
any ideas?
thanks