Script:<script>
var int=self.setInterval(function(){clock()},1000);
function clock()
{
var d=new Date();
var t=d.toLocaleTimeString();
document.getElementById("clock").value=t;
}
</script>
HTML CODE: <body>
<input type="text" id="clock" />
<button onclick="int=window.clearInterval(int)">Stop</button>
</body>