if (persons.value == "") {
                totalValue.textContent = 0;
            } else {
                totalValue.textContent = total; 
            }persons.addEventListener("change", function() {
            if (restDays.value == "" || restDays.value == 0 || persons.value == "" || persons.value == 0) {
                totalValue.textContent = 0;
            }
        });