<!DOCTYPE html>
<html lang="en-US">
<body>
<button onclick="myFunction()">Start Count Down</button>
<p id="point"></p>
<script>
var count = 0;
var x = document.getElementById("point");
function myFunction(){
setInterval(function(){
count = count + 1;
x.innerHTML = count;
},1000)
}
</script> </body>
</html>