Needing help with a practical joke at work

[Inglorion]

Well....I know that once upon a time, you were able to send messages to a specified computer in a network by using some sort of command which would put the message in a small pop-up window on the recieving computer....anyone know if that is still possible or not and in case it is, how to do it (and what I would need to know about the recieving computer to direct it to it)?

[Gninja]

net send computer_name message in dos mode