Disable delete event

[Anders Melchiorsen <and kampsax dtu dk>]

I have a window that I would like to not react to user requests for
closing the window. Right now I am ignoring the delete event which
works fine - but how do I tell the window manager that it should not
make a close button (xdvi does this, for example) ?

I could not find any gtk+ function to do this; will I have to make X
calls to do it?
-- 
Mvh. Anders