TODO 
· User can connect to a user-friendly Exchange system:
	· login with a nickname
	· listing of existing stock options (at connection)
	· subscription to one or more stock options (or unsubscription)
· help available (command list, stock options list...)
	· Subscribers to a stock option are warned when the quote changes:
	· random variation of the quote
	· complete information in warning messages
	· disconnection from the system causes unsubscription
	· An administration interface is expected:
	· definition of new stock options
· deletion of dead options (notification to subscribers)
	· options with null quote are automatically deleted
	· make use of EJB when desired

Client side :
	2 GUI 
		client GUI. It lets you to connect to the server, display stockOption, subscribe/unsubscribe to these stockOptions and disconect.
		Admin Gui. It permits you to add/remove stock options 

Server side : 
	The server has to keep a list of stock options.
 	Those stockOptions will have their quotes change randomly.
	A rmi communication can be used to communicate with clients
	The best solution could be a message-driven bean. It's an EJB after all...