Jquery 實現頁面倒數計時的功能

最近碰到個頁面要顯示倒數計時的功能。因為不可能去一直ajax請求資料庫獲取最新的時間，只有在頁面也去實時的變更倒數計時。

var timer = setInterval(function () {
				/*獲取datagrid的時間列的資訊  */
                var tdList = $('#report1 .datagrid-body [field=TIME_COUNTDOWN] div');
                for (var i = 0; i < tdList.length; i++) {
                    var Temp = tdList[i].innerText.split(':');

                    var Seconds = 60 * Number(Temp[0]) + Number(Temp[1]);
                    if (Seconds <= 0) {
                        result = tdList[i].innerText;

                    } else {
                        var time = Seconds - 1;

                        var theTime = parseInt(time);// 秒
                        var middle = 0;// 分

                        if (theTime > 60) {
                            middle = parseInt(theTime / 60);
                            theTime = parseInt(theTime % 60);
                        }
                        var result = parseInt(theTime);
                        if (middle > 0) {
                            result = LeftMake(parseInt(middle), 2) + ":" + LeftMake(result, 2);
                        } else {
                            result = "00:" + LeftMake(result, 2);
                        }
                        tdList[i].innerText = result;
                    }
                }

            }, 1000);