int getMoney(int cardID, String password, float getMoneyNumber) {
        int errorNumber = 0;
        if (hasMember(cardID)) {
            if (isPasswordRight(cardID, password)) {
                for (Member a : userList) {
                    int index;
                    if (a.cardID == cardID) {
                        index = userList.indexOf(a);
                        if (userList.get(index).myMoney >= getMoneyNumber) {
                            userList.get(index).myMoney -= getMoneyNumber;
                        } else errorNumber = 3; //3 is Money is not enough
                        break;
                    }
                }
            } else errorNumber = 2; //password not right
        } else errorNumber = 1; //no user
        return errorNumber; //0 is no problem
    }