Javascript 如何设置倒计时计时器在00:00:00或当=0时停止自动单击按钮

当我的计时器转到00:00:00时，下一秒将继续倒数，如23:59:59。 如何在00:00:00或计时器=00:00:00自动单击按钮时停止计时器

钮扣

<input type=submit name=submit value='Get Result' id='submitpaper'>

这是我的回复

<?php
session_start();

$from_time1=date('Y-m-d H:i:s');
$to_time1=$_SESSION["end_time"];
$timefirst=strtotime($from_time1);
$timesecond=strtotime($to_time1);

$differenceinseconds=$timesecond-$timefirst;
echo gmdate("H:i:s",$differenceinseconds);

?>

---

您可以编辑对php的响应

<?php
session_start();

$from_time1=date('Y-m-d H:i:s');
$to_time1=$_SESSION["end_time"];
$timefirst=strtotime($from_time1);
$timesecond=strtotime($to_time1);
$differenceinseconds=$timesecond-$timefirst;
//if countdown smaller than 0, countdown should be 0
if($differenceinseconds<0)$differenceinseconds=0;

echo gmdate("H:i:s",$differenceinseconds);

?>

---

谢谢您的帮助，您知道当$differenceinconds=0时如何提交表单或自动单击按钮吗

<?php
session_start();

$from_time1=date('Y-m-d H:i:s');
$to_time1=$_SESSION["end_time"];
$timefirst=strtotime($from_time1);
$timesecond=strtotime($to_time1);

$differenceinseconds=$timesecond-$timefirst;
echo gmdate("H:i:s",$differenceinseconds);

?>

    var x = setInterval(test,1000); 
function test()
{
    var xmlhttp=new XMLHttpRequest();
    xmlhttp.open("GET","response.php",false);
    xmlhttp.send(null);
    document.getElementById("response").innerHTML=xmlhttp.responseText;
}

<?php
session_start();

$from_time1=date('Y-m-d H:i:s');
$to_time1=$_SESSION["end_time"];
$timefirst=strtotime($from_time1);
$timesecond=strtotime($to_time1);
$differenceinseconds=$timesecond-$timefirst;
//if countdown smaller than 0, countdown should be 0
if($differenceinseconds<0)$differenceinseconds=0;

echo gmdate("H:i:s",$differenceinseconds);

?>