unable to modify button thickness

[vprasad applix com (V G Prasad [ext 294])]

Hi,
I am unable to modify the button thickness(depth).
 I thought gtk_container_border_width (GTK_CONTAINER (button), 5);
will solve the problem but this just changes the button size.
What I am looking for is a method to increase/decrease the shadow thickness  that is drawn around the button so that it will give a change in button thickness.
2. Is it possible to change the x(y)thickness on style->klass?  
vg
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V G Prasad
Email:vprasad@applix.com