function calcage(secs, num1, num2) {
  s = ((Math.floor(secs/num1))%num2).toString();
  if (LeadingZero && s.length < 2)
    s = "0" + s;
  return s;
}

function CountBack(secs) {
  if (secs < 0) {
    document.getElementById("countdown").innerHTML = FinishMessage;
    return;
  }
  var DisplayStr = DisplayFormat;
  DisplayStr0 = calcage(secs,86400,100000).charAt(0);
  DisplayStr1 = calcage(secs,86400,100000).charAt(1);
  DisplayStr = DisplayStr.replace(/%%D1%%/g,'<span class="section"><span class="num' + DisplayStr0 + '"></span>');
  DisplayStr = DisplayStr.replace(/%%D2%%/g,'<span class="num' + DisplayStr1 + '"></span> day</span>');
  
  DisplayStr0 = calcage(secs,3600,24).charAt(0);
  DisplayStr1 = calcage(secs,3600,24).charAt(1);
  DisplayStr = DisplayStr.replace(/%%H1%%/g,'<span class="section"><span class="num' + DisplayStr0 + '"></span>');
  DisplayStr = DisplayStr.replace(/%%H2%%/g,'<span class="num' + DisplayStr1 + '"></span> hr</span>');
  
  DisplayStr0 = calcage(secs,60,60).charAt(0);
  DisplayStr1 = calcage(secs,60,60).charAt(1);
  DisplayStr = DisplayStr.replace(/%%M1%%/g,'<span class="section"><span class="num' + DisplayStr0 + '"></span>');
  DisplayStr = DisplayStr.replace(/%%M2%%/g,'<span class="num' + DisplayStr1 + '"></span> min</span>');
  
  DisplayStr0 = calcage(secs,1,60).charAt(0);
  DisplayStr1 = calcage(secs,1,60).charAt(1);
  DisplayStr = DisplayStr.replace(/%%S1%%/g,'<span class="section"><span class="num' + DisplayStr0 + '"></span>');
  DisplayStr = DisplayStr.replace(/%%S2%%/g,'<span class="num' + DisplayStr1 + '"></span> sec</span>');

  document.getElementById("countdown").innerHTML = DisplayStr;
  if (CountActive)
    setTimeout("CountBack(" + (secs+CountStepper) + ")", SetTimeOutPeriod);
}

if (typeof(BackColor)=="undefined")
  BackColor = "white";
if (typeof(ForeColor)=="undefined")
  ForeColor= "black";
if (typeof(TargetDate)=="undefined")
  TargetDate = "12/31/2020 5:00 AM";
if (typeof(DisplayFormat)=="undefined")
  DisplayFormat = "%%D1%% %%D2%% %%H1%% %%H2%% %%M1%% %%M2%% %%S1%% %%S2%%";
if (typeof(CountActive)=="undefined")
  CountActive = true;
if (typeof(FinishMessage)=="undefined")
  FinishMessage = "";
if (typeof(CountStepper)!="number")
  CountStepper = -1;
if (typeof(LeadingZero)=="undefined")
  LeadingZero = true;
if (typeof(CurrentTime)=="undefined")
  CurrentTime = new Date();


CountStepper = Math.ceil(CountStepper);
if (CountStepper == 0)
  CountActive = false;
var SetTimeOutPeriod = (Math.abs(CountStepper)-1)*1000 + 990;
//putspan(BackColor, ForeColor);
var dthen = new Date(TargetDate);
var dnow = new Date(CurrentTime);
if(CountStepper>0)
  ddiff = new Date(dnow-dthen);
else
  ddiff = new Date(dthen-dnow);
gsecs = Math.floor(ddiff.valueOf()/1000);
CountBack(gsecs);