import java.rmi.*;
import java.util.Vector;

/**
  *This inteface defines the server objects methods.
  */
public interface PopupServerInterface extends Remote{

/**
  *Method to add a user on the server. 
  *Basically regiseters a client with the server
  *@param userId, the remote interface representing the client object
  */
	
public void addUser(PopupClientInterface userId)  throws 
       RemoteException;

/**
  *Method to remove a registerd user onthe server.
  *Called by the client in its destroy before going down.
  *@param userId, the remote interface representing the client object
  */
     
public void removeUser(PopupClientInterface userId)  throws RemoteException ;

/**
  *Returns a listing of all the registerd users at any point of time.
  *@return The vector containing all the references to the clients
  */
public Vector getUsers()  throws RemoteException ;

/**
  *Sends a message to all the registerd  clients.
  *@param String containing the message to be brodcast.
  */
public void sendMessage(String message) throws RemoteException ;

}