public void login (String id, String password) {
        util.Utility.DEBUG(0, "test");
        if (staffs.containsKey(id)) {
            // 有這個人
            if ( staffs.get(id).password().equals(password)) {
                // 密碼正確。開始登入
                Staff aStaff = staffs.get(id);
                
                switch( aStaff.occupation() ) {
                case doctor:
                    util.Utility.DEBUG(0, "" + aStaff.name() + "醫生登入, 加入DoctorStorage中");
                    DoctorStorage.Instance().put(id, new Doctor(aStaff.name(), aStaff.email(), aStaff.occupation(), aStaff.id(), aStaff.password()));
                    new DoctorMainView(aStaff).setVisible(true);
                    break;
                case nurse:
                    new NurseMainView(aStaff).setVisible(true);
                    break;
                case counterStaff:
                    new CounterStaffMainView(aStaff).setVisible(true);
                    break;
                case inspector:
                    new InspectorMainView(aStaff).setVisible(true);
                    break;
                case pharmacist:
                    new PharmacistMainView(aStaff).setVisible(true); 
                    break;
                case patrolNurse:
                    util.Utility.DEBUG(0, "" + aStaff.name() + "巡診護士登入, 加入PatrolNurseStorage中");
                    new PatrolNurseMainView(aStaff).setVisible(true);
                    PatrolNurseStorage.Instance().put(id, new PatrolNurse(aStaff.name(), aStaff.email(), aStaff.occupation(), aStaff.id(), aStaff.password()));
                    break;
                default:
                    System.out.println("未知的職業 ？！結束程式...");
                    System.exit(1);
                }
                
                JOptionPane.showMessageDialog(null, "歡迎登入，" + aStaff.name() + aStaff.occupation() + "。");
            } else {
                // 有這個人但密碼打錯了
                JOptionPane.showMessageDialog(null, "密碼錯誤:'<");
            }
        } else {
            // 查無此人
            JOptionPane.showMessageDialog(null, "抱歉，這個id沒有註冊過喔^^\"");
        }
    }