I am trying to make a clock that ticks in the status bar. It displays the correct time, but it doesn't update every second. What is wrong with the code?

PHP Code:
<html>
<head>
<title>Clock</title>
<script>
var today = new Date();
var hours;
var minutes;
var seconds;
var ampm;
var total;

function updateTimer()
{
    hours = today.getHours();
    minutes = today.getMinutes();
    seconds = today.getSeconds();
    ampm = "AM";

    if (hours >= 12)
        ampm = "PM";

    if (hours >= 12)
        hours -= 12;

    if (minutes < 10)
        minutes = "0" + minutes;

    if (seconds < 10)
        seconds = "0" + seconds;

    total = hours + ":" + minutes + ":" + seconds + " " + ampm;
    window.status = total;

    setTimeout("updateTimer()", 1000);
}

</script>
</head>
<body onLoad="updateTimer()">
</body>
</html>