var tmr_nMins;
var tmr_nSecs;

tmr_nMins = 0;
tmr_nSecs = 5;

function fTimerStart(in_nMins)
{
	tmr_nMins = in_nMins;
	fTimerRun();
	window.setInterval(fTimerRun, 5000) 
}

function fTimerRun()
{ 
	nSecs     = tmr_nMins*60+tmr_nSecs -5;
	tmr_nMins = parseInt(nSecs/60);
	tmr_nSecs = nSecs%60;


	if(nSecs<110)
	{
		if(nSecs%2==0)
			document.getElementById("txtTimer").className = "instmr2";
		else
			document.getElementById("txtTimer").className = "instmr1";
	}

	document.getElementById("txtTimer").value = fPadl(tmr_nMins+"",2,"0") + ":" + fPadl(tmr_nSecs+"",2,"0"); 
	fOnScroll();
}

function fPadl(in_nNum, in_nSize, in_cChr) 
{
    cStr = String(in_nNum);
    while (cStr.length < in_nSize)
        cStr = in_cChr + cStr;
    return cStr;
}

function fOnScroll()
{
	document.getElementById("spnTimer").style.top  = 60+document.body.scrollTop;
	document.getElementById("spnTimer").style.left = 0+document.body.scrollLeft;
}