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

function putspan(backcolor, forecolor) {
 document.write("<span id='countdown' 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();

//dnow.setHours(dnow.getHours()+22);
//alert(dnow);
if(CountStepper>0)
  ddiff = new Date(dnow-dthen);
else
  ddiff = new Date(dthen-dnow);
gsecs = Math.floor(ddiff.valueOf()/1000);
CountBack(gsecs);

/*
function countdown_clock(year, month, day, hour, minute, format)
         {
         //I chose a div as the container for the timer, but
         //it can be an input tag inside a form, or anything
         //who's displayed content can be changed through
         //client-side scripting.
         //html_code = '<div id="countdown"></div>';
         
         //document.write(html_code);
         
         countdown(year, month, day, hour, minute, format);                
         }
         
function countdown(year, month, day, hour, minute, format)
         {
            
         Today = new Date();
         Todays_Year = Today.getFullYear() - 2000;
         //alert(Todays_Year);
         Todays_Month = Today.getMonth() + 1;                  
         
         //Convert both today's date and the target date into miliseconds.                           
         Todays_Date = (new Date(Todays_Year, Todays_Month, Today.getDate(), 
                                 Today.getHours(), Today.getMinutes(), Today.getSeconds())).getTime();                                 
         Target_Date = (new Date(year, month, day, hour, minute, 00)).getTime();
         //alert(Target_Date);
         
         //Find their difference, and convert that into seconds.                  
         Time_Left = Math.round((Target_Date - Todays_Date) / 1000);
         //Time_Left = Math.round((Todays_Date-Target_Date  ) / 1000);
         //alert(Time_Left);
         var obj = document.getElementById('countdown');
         //alert(obj);
         if(Time_Left < 0)
            Time_Left = 0;
         format=1;
         switch(format)
               {
               case 0:
                    //The simplest way to display the time left.
                    obj.innerHTML = Time_Left + ' seconds';
                    break;
               case 1:
                    //More datailed.
                    days = Math.floor(Time_Left / (60 * 60 * 24));
                    Time_Left %= (60 * 60 * 24);
                    hours = Math.floor(Time_Left / (60 * 60));
                    Time_Left %= (60 * 60);
                    minutes = Math.floor(Time_Left / 60);
                    Time_Left %= 60;
                    seconds = Time_Left;
                    
                    dps = 's'; hps = 's'; mps = 's'; sps = 's';
                    //ps is short for plural suffix.
                    if(days == 1) dps ='';
                    if(hours == 1) hps ='';
                    if(minutes == 1) mps ='';
                    if(seconds == 1) sps ='';
                    if (hours<10) hours = "0"+hours;
                    if (minutes<10) minutes = "0"+minutes;
                    if (seconds<10) seconds = "0"+seconds;
                    //obj.innerHTML = days + ':' + dps + ' ';
                    obj.innerHTML = hours + ':';
                    obj.innerHTML += minutes + ':' ;
                    obj.innerHTML += seconds ;
                    //alert(obj.innerHTML);
                    break;
               default: 
                    obj.innerHTML = Time_Left + '';
               }
               
         //Recursive call, keeps the clock ticking.
         //setTimeout('countdown(' + year + ',' + month + ',' + day + ',' + hour + ',' + minute + ',' + format + ');', 1000);
         setTimeout("countdown('" + year + "','" + month + "','" + day + "','" + hour + "','" + minute + "','" + format + "');", 1000);
         }
 */