如何让Javascript倒计时器时间到0时停止计时

来源：百度知道 编辑：UC知道 时间：2024/05/30 05:29:45
目前写了个倒计时器,时间归到0时还继续倒计时
(也就是显示负的数字时间)
如何到0时直接停止不再计时?

<script>

function createtime()
{
var now = new Date();
var grt= new Date("01/15/2010 18:00:00");
var timespan = new Date(grt-now) ;
timespan = timespan.getTime();

//now.setTime(now.getTime()+250);
days = (timespan) / 1000 / 60 / 60 / 24;
dnum = Math.floor(days);
hours = (timespan) / 1000 / 60 / 60 - (24 * dnum);
hnum = Math.floor(hours);
if(String(hnum).length ==1 ){hnum = "0" + hnum;}
minutes = (timespan) / 1000 /60 - (24 * 60 * dnum) - (60 * hnum);
mnum = Math.floor(minutes);
if(String(mnum).length ==1 ){mnum = "0" + mnum;}
seconds = (timespan) / 1000 - (24 * 60 * 60 * dnum) - (60 * 60 * hnum) - (60 * mnum);
snum = Math.round(seconds);
if(String(snum).length ==1 ){snum = "0" + snum;}

document.getElementById("timeDate").innerHTM

我给你我的代码，你参考一下，把这些放在<head>和</head>之间
<span id="clock">00:00:05:00</span>
<input id="startB" type="button" value="start countdown!" onclick="run()">
<input id="endB" type="button" value="stop countdown!" onclick="stop()">
<br>
<input id="diff" type="text">
<input id="next" type="text">
<script language="Javascript">
var normalelapse = 100;
var nextelapse = normalelapse;
var counter;
var startTime;
var start = clock.innerText;
var finish = "00:00:00:00";
var timer = null;

// 开始运行
function run() {
startB.disabled = true;
endB.disabled = false;
counter = 0;
// 初始化开始时间
startTime = new Date().valueOf();

// nextelapse是定时时间, 初始时为100毫秒
// 注意setIn