deleting widgets

[Jeff <schizm pc-4374 bc rogers wave ca>]

ok, this may be a fundamental widget set question that I should know, 
but this is pretty much my first widget set programming experience 
(im usually raw xlib with a tad of athena).

once I define a window, put in a menubar, have a bunch of widgets taking
up areas of the window, how do I 'delete' those widgets so that I can
put other ones in their place?  lets say the program starts, the whole window
is dedicated to a GtkImage for a title screen, then i want the GtkImage
to go away, and some other widgets to replace it.....

thanks

Jeff