Show Timer on status bar using Javascript

function showtime ()
{

var now = new Date();
var hours = now.getHours();
var minutes = now.getMinutes();
var seconds = now.getSeconds()
var timeValue = "" + ((hours >12) ? hours -12 :hours)
timeValue += ((minutes < 10) ? ":0" : ":") + minutes
timeValue += ((seconds < 10) ? ":0" : ":") + seconds
timeValue += (hours >= 12) ? " P.M." : " A.M."

window.status = timeValue;

}

Call this function on load of the form.