setting maximum window size

[Nick Soffe <nick soffe bioch ox ac uk>]

Hi,
I would like to restrict the maximum width of the top level window in an
application I've written for gtk2.x. I don't want to prevent the user from
resizing altogether. The window contains various resizable widgets
including a drawingarea on which I've set the minimum size with a
gtk_widget_set_size_request. Sorry if this is well known but after
searching the docs I'm still unsure of the correct way to achieve this
under gtk2.x.
Things I would have tried under gtk1.x seem to be deprecated. I also
realise the window manager will probably have the last word.
Thanks for any help,
Nick Soffe.