To run my program follow the steps below.

Step:
1. Change to my project's directory.

2. Input command : rmiregistry

3. In a new command-line window Input command : java MessageCenter

4. Start another command-line window 
 
	If The client and server run on the same machine Input :
		java Client localhost 1099 

	If the client and server run on different machine 
	put the Client.java and RMIIntf.java on one machine and 
	put all the other .java file on another machine
	Then run MessageCenter.class(Server) and Client.class  
	In client-end Input :	
		java Client RemoteHostIP 1099