javcript timer控制

<script type="text/javascript">
var num = 0;
//间隔一秒循环执行
var id = setInterval(function ()
{
num = num + 1;
document.getElementById("ss").value = num;
}, 1000);

//间隔一秒执行一次
var ids = setTimeout(function () {
num = num + 1;
document.getElementById("ss").value = num;
}, 1000);
//停止方法
function stopModth() {
clearInterval(id);
clearTimeout(ids);
}
</script>