VS Code зачеркивает "event" и пишет в отладке: Ожидалось "while", при написании кода JS. Что это?

var youAnswers = [];
do { //выводим первый вопрос
    ok = false;
    event = +prompt(works.a00 + works.a1 + works.a2 + "-1 - Exit the Game");
    if (event == -1) {
        break;
    } else {
        ok = isAnswer(works.a0, event);
        if (ok) {
            if (event == 1) {
                youAnswers.push(works.a1);
            } else {
                youAnswers.push(works.a2)
            }
        }
    }
} while (!ok);
switch (event) {
    case 1:
        do {
            ok = false;
            event = +prompt(works.b00 + works.b1 + works.b2 + "-1 - Exit the Game");
            if (event == - 1) {
                break;
            } else {
                ok = isAnswer(works.b0, event);
                if (ok) {
                    if (event == 1) {
                        youAnswers.push(works.b1);
                    } else {
                        youAnswers.push(works.b2)
                    }
                }
            }
        } while (!ok);
        switch (event) {
            case 1:
                do {
                    ok = false;
                    event = +prompt(works.d00 + works.d1 + works.d2 + "-1 = Exit the Game");
                    if (event == -1) {
                        break;
                    } else {
                        ok = isAnswer(works.d0, event);
                        if (ok) {
                            if (event == 1) {
                                youAnswers.push(works.d1);
                            } else {
                                youAnswers.push(works.d2)
                            }
                        }
                    }
                } while (!ok);

                break;
            case 2:
        }