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) {
   if (secs < 0) {
      document.getElementById("cntdwn").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("cntdwn").innerHTML = DisplayStr;
   if (CountActive)
      setTimeout("CountBack(" + (secs + CountStepper) + ")", SetTimeOutPeriod);
}

function putspan(backcolor, forecolor) {
   document.write("<span id='cntdwn' style='background-color:" + backcolor +
                "; color:" + forecolor + "'></span>");
}

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;


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();
if (CountStepper > 0) var ddiff = new Date(dnow - dthen);
else ddiff = new Date(dthen - dnow);
gsecs = Math.floor(ddiff.valueOf() / 1000);
CountBack(gsecs);