how to show menu tooltip in statusbar with libglademm?

[Liangxu Wang <wlx mygis org>]

Hi,
	I am study gtkmm now, and after some search about the statusbar with
google, I have not get the answer on how to show menu tooltip in
statusbar, so can you tell me how to do this?
	for e.g., I create the mainwindow in a glade file,after load the glade
file, how to show menu's tooltip in statusbar?
	
Sincerely yours,
Liangxu Wang