Interface for class Session

class Session
  {
    /* PURPOSE: Manage a session with a single user.
    */

    public:

	Session(int cardNumber);

	// Run session until user is through or some exceptional condition
	// prevents further processing

	void doSessionUseCase();

	// Force user to re-enter PIN if bank says original PIN was invalid.
	// Return final code from resubmission to bank.

	Bank::ApprovalCode doInvalidPINExtension();

	// Each transation obtains this information from the session when it
	// is needed

	int cardNumber() const;
	int PIN() const;

    private:

	enum { RUNNING, ABORTED } _state;
 	int			  _cardNumber;
	int 			  _PIN;
	class Transaction * 	  _currentTransaction;
  };

//