JavaScript 获取星期几函数

function getDayofWeek() {
            var day = "";
            var time = new Date();
            var numOfWeek = time.getDay();
            switch (numOfWeek) {
                case 0:
                    day = "星期日";
                    break;
                case 1:
                    day="星期一";
                    break;
                case 2:
                    day = "星期二";
                    break;
                case 3:
                    day = "星期三";
                    break;
                case 4:
                    day = "星期四";
                    break;
                case 5:
                    day = "星期五";
                    break;
                case 6:
                    day = "星期六";
                    break;
            }
            document.getElementByIdx_x("DayOfWeek").innerHTML = day;
        }
    </script>