The client side program is intended to start with Windows.
It continually runs in the background of the OS, with no visual distractions.
The client 'listens' on a port and waits for a connection from the server
When data is received from the server, a small 'OK' reply is sent, alerting the server that the message was delivered with success.
Then the data received compiled into a string of characters displayed in a dialog box.
The dialog box displayed on the client machine is system modal - meaning that is is always on top of all other programs until it is dismissed.
When a network administrator wants to send a message to a client s/he does so
by composing the message on the server side program.
First s/he must specify the IP address or computer name of the remote system.
The title of the dialog box, type of icon/sound used, and the actual message text are specified and then the 'Send' button is clicked.
If the message is sent with success and the client side program returns an 'OK' alert, then the server displays a 'Message sent' confirmation.