update time with javascript

<!--
/////////////////////////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////////////////
///////
///////   Author : EAKKASIT TUNSAKOOL
///////
///////   ref     : http://www.plus2net.com/javascript_tutorial/clock.php
///////
/////////////////////////////////////////////////////////////////////////////
-->
<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>time</title>
</head>
<body>
	<script type="text/javascript">
	function updateTime(){
    var currentTime = new Date()
    var hours = currentTime.getHours()
    var minutes = currentTime.getMinutes()
    var seconds = currentTime.getSeconds()
    if (seconds<=9){
	seconds="0"+seconds
	}
    if (minutes < 10){
        minutes = "0" + minutes
    }
    var t_str = hours + ":" + minutes + " "+":"+seconds;
    if(hours > 11){
        t_str += "PM";
    } else {
        t_str += "AM";
    }

    document.getElementById('time_span').innerHTML = t_str;
}
setInterval(updateTime, 1000);
	</script>
	<div id="time_span">time</div>
</body>
</html>