/*
Author: Robert Hashemian
http://www.hashemian.com/

You can use this code in any manner so long as the author's
name, Web address and this disclaimer is kept intact.
********************************************************
Usage Sample:

<script language="JavaScript">
TargetDate = "12/31/2020 5:00 AM";
BackColor = "palegreen";
ForeColor = "navy";
CountActive = true;
CountStepper = -1;
LeadingZero = true;
DisplayFormat = "%%D%% Days, %%H%% Hours, %%M%% Minutes, %%S%% Seconds.";
FinishMessage = "It is finally here!";
</script>
<script language="JavaScript" src="http://scripts.hashemian.com/js/countdown.js"></script>
*/

function trim_number(s) {
  while (s.substr(0,1) == '0' && s.length>1) { s = s.substr(1,9999); }
  return s;
}

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("cntdwn").innerHTML = FinishMessage;
    return;
  }
  var calcage_days = trim_number(calcage(secs,86400,100000));  
  var calcage_hours = trim_number(calcage(secs,3600,24));
  var calcage_minutes = trim_number(calcage(secs,60,60));
  var calcage_secs = trim_number(calcage(secs,1,60));
  
  if(calcage_days == "0") calcage_days = "";
  else if(calcage_days == "1") calcage_days += " day";
  else calcage_days += " days";
  
  if((calcage_days == "0") && (calcage_hours == "0")) calcage_hours = "";
  else if(calcage_hours == "1") calcage_hours += " hour";
  else calcage_hours += " hours";
  
  if((calcage_days == "0") && (calcage_hours == "0") && (calcage_minutes == "0"))  calcage_minutes = "";
  else if(calcage_minutes == "1") calcage_minutes += " minute";
  else calcage_minutes += " minutes";
  
  if(calcage_secs == "1") calcage_secs += " second";
  else calcage_secs += " seconds";


  DisplayStr = DisplayFormat.replace(/%%D days%%/g, calcage_days);  
  DisplayStr = DisplayStr.replace(/%%H hours%%/g, calcage_hours);
  DisplayStr = DisplayStr.replace(/%%M minutes%%/g, calcage_minutes);
  DisplayStr = DisplayStr.replace(/%%S seconds%%/g, calcage_secs);

  if(document.getElementById("cntdwn")) document.getElementById("cntdwn").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 = "12/31/2010 5:00 AM";
if (typeof(StartDate)=="undefined")   StartDate = new Date();
if (typeof(DisplayFormat)=="undefined") DisplayFormat = "%%D days%% %%H hours%% %%M minutes%% %%S seconds%% left!";
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;
var dthen = new Date(TargetDate);
var dnow = new Date(StartDate);
if(CountStepper>0) ddiff = new Date(dnow-dthen);
else ddiff = new Date(dthen-dnow);
gsecs = Math.floor(ddiff.valueOf()/1000);
CountBack(gsecs);