Make an entire window insensitive?

[Jeff Garzik <jgarzik pobox com>]

I'm interested in popping-up a progress dialog while my app does some
work.  This dialog appears as the child of another dialog.

The parent dialog is not modal, but when the progress dialog appears, I
don't want the user to be able to do anything in the parent, until the
operation completes and the progress dialog disappears.

The best thing I can come up with is keeping track of all the widgets in
the dialog and toggling the insensitivity of each.  That seems messy. 
Is there a single function that will make an entire dialog disabled, or
insensitive, or similar?

Thanks,

	Jeff