var tags_before_clock = " ";
var tags_after_clock  = " ";


document.write('<div id="clock"></div>');

function upclock(){ 
var dte = new Date();
var hrs = dte.getHours();
var min = dte.getMinutes(); 
var sec = dte.getSeconds();
var col = ":";
var spc = " ";

if (hrs == 0) hrs=12;
if (min<=9) min="0"+min;
if (sec<=9) sec="0"+sec;

document.getElementById('clock').innerHTML = tags_before_clock+hrs+col+min+col+sec+spc+tags_after_clock;
}
setInterval("upclock()",1000);