function tick() {
var hours, minutes, seconds, ap;
var intHours, intMinutes, intSeconds;
var today;

today = new Date();

intHours = today.getHours();
intMinutes = today.getMinutes();
intSeconds = today.getSeconds();

if (intHours == 0) {
hours = "0:";
ap = "";
}
else if (intHours < 12) { 
hours = intHours+":";
ap = "";
}
else if (intHours == 12) {
hours = "12:";
ap = "";
}
else {
intHours = intHours - 0
hours = intHours + ":";
ap = "";
}
if (intMinutes < 10) {
minutes = "0"+intMinutes+":";
}
else {
minutes = intMinutes+":";
}
if (intSeconds < 10) {
seconds = "0"+intSeconds+" ";
}
else {
seconds = intSeconds+" ";
} 

timeString = hours+minutes+seconds+ap;
Clock.innerHTML = timeString;
window.setTimeout("tick();", 100);
}
window.onload = tick;