Indicating selected region on pixmap

[Keith McDade <kmcdade 454 com>]

Howdy All,

I am doing an application where I have a gtk_pixmap inside a gtk_event_box,
all within their own parent window.  The user is supposed to select a region
by click and drag.  All that works fine but I need to draw a rectangle
indicating the selected region which should be updated until the user
releases the mouse button.  This would preferably be done without disturbing
the image underneath.  Can anyone give me a clue about how
gdk_draw_rectangle works?  Should I be using the window, the event_box or
the pixmap as the drawable?  None of the above?  Is this even a good way to
do it?  Any suggestions greatlt appreciated.

Hope all is well