var globalDiff = 0;

function clockTick()
{
	var currentTime = new Date();
	var glTime = new Date(currentTime.getTime() - globalDiff.getTime());
	hours = glTime.getHours(); 
	mins = glTime.getMinutes(); 
	secs = glTime.getSeconds(); 
	document.getElementById("clock").innerHTML = ((hours<10)?('0'+hours):hours)+":"+((mins<10)?('0'+mins):mins);
	setTimeout("clockTick()", 15000);
}

function setFirstTime(hh, mm, ss){
	var glTime = new Date();
	var localTime = new Date();
	glTime.setHours(hh);
	glTime.setMinutes(mm);
	glTime.setSeconds(ss);
	globalDiff = new Date(localTime.getTime() - glTime.getTime());
	clockTick();
}