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

function CountBack(secs, spanID, SetTimeOutPeriod) {
  if (secs < 0) {
    document.getElementById(spanID).innerHTML = FinishMessage;
    return;
  }
  DisplayStr = DisplayFormat.replace(/%%D%%/g, calcage(secs,86400,100000));
  DisplayStr = DisplayStr.replace(/%%H%%/g, calcage(secs,3600,24));
  DisplayStr = DisplayStr.replace(/%%M%%/g, calcage(secs,60,60));
  DisplayStr = DisplayStr.replace(/%%S%%/g, calcage(secs,1,60));

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

function myCountBack(secs,spanID) {
  if (secs < 0) {
    document.getElementById(spanID).innerHTML = FinishMessage;
    return;
  }
  DisplayStr = DisplayFormat.replace(/%%D%%/g, calcage(secs,86400,100000));
  DisplayStr = DisplayStr.replace(/%%H%%/g, calcage(secs,3600,24));
  DisplayStr = DisplayStr.replace(/%%M%%/g, calcage(secs,60,60));
  DisplayStr = DisplayStr.replace(/%%S%%/g, calcage(secs,1,60));

  document.getElementById(spanID).innerHTML = DisplayStr;

  if (this.CountActive)
    setTimeout("CountBack(" + (secs+CountStepper) + ",'"+(spanID)+"',"+this.SetTimeOutPeriod+")", this.SetTimeOutPeriod);
}

function myputspan(spanID) {
 document.write("<span id='"+spanID+"' style='background-color:" + BackColor + 
                "; color:" + ForeColor + "'></span>");
}


function countDown(_TargetDate, spanID){
	this.TargetDate = _TargetDate;
	this.SpanID = spanID;
	if (typeof(this.CountActive)=="undefined")
	  this.CountActive = true;
	CountStepper = Math.ceil(CountStepper);
	if (CountStepper == 0)
	  this.CountActive = false;
	this.SetTimeOutPeriod = (Math.abs(CountStepper)-1)*1000 + 990;
	this.span = myputspan;
	this.span(spanID);
	var dthen = new Date(this.TargetDate);
	var dnow = new Date();
	if(this.CountStepper>0)
	  ddiff = new Date(dnow-dthen);
	else
	  ddiff = new Date(dthen-dnow);
	this.gsecs = Math.floor(ddiff.valueOf()/1000);
	this.countBack = myCountBack;
	this.countBack(this.gsecs,this.SpanID);
}

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 = "%%D%% Days, %%H%% Hours, %%M%% Minutes, %%S%% Seconds.";
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(SpanID)=="undefined")
  SpanID = 'cntdwn';