Is there a Wall message for GNOME or KDE

[Leslie S Satenstein]

I would like to send an alert about a system change or an alert to all gnome users that
the system is going offline for maintenance at a certain time. 

What is the equivalent to the wall function that pops up a window in kde or gnome with the
message in a window that must be acknowledged.

------------------

Regards  
Mr. Leslie
 Leslie Satenstein

voice:  514-369-1685    
mailto:[e-mail]