help with gtk/gnome property box

[Jim Cadien <jcadien1 cox net>]

I am essentially brand new to widget 
programming.  I am modifying a pre-existing 
program.
The program has an array of default parameter 
values, which I want the users to be able to 
modify while the program is running.  I have 
Peter Wright's book on beginning gtk/gnome 
programming.  There is example code in ch 12, 
called propertybox.c.  It looks  exactly like 
what I need, but it is very skeleton in 
nature. It presents a window with entry 
boxes.  User can enter data.  I cannot find 
where the entered data are stored.  In fact 
maybe they are not.
I really would like to know:
1. in this program when data are entered into 
a box, how can I grab them?
2. I would like to put the default values 
into the dialog boxes when they first 
appear...to be       edited by the user.
3.  Anything else I need to know to get this 
working in my program.

Thanks,
Jim Cadien