JSFiddle - React, Tailwind, and code Playground

by Academia

HTML

<p id="test"></p>
<form name="form1">
    Enter timeout value:<input type="text" id="to"/></br></br>
    Countdown: <input type="text" id="cd"/></br></br>
    <input type="button" value="Start" onclick="start()" />
    <input type="button" value="Stop" onclick="stop()" />
</form>

JavaScript

var timer;
function start(){
    alert("hello");
    document.getElementById("test").innerHTML = "test";
    timer = setInterval(function(){myTimer()},1000);
}

function myTimer(){
    var value = Number(document.getElementById("to").value);
    if (value != 0){
        document.getElementById("to").value = value - 1;
    } else {
        stop();
    }
}

function stop(){
    clearInterval(timer);
}