var day = 725;
var hou = 2;
var min = 32;
var sec = 5;

function update()
{
  var dsec = sec;
  var dhou = hou;
  var dmin = min;
  sec = sec - 1;
  if (sec < 10) dsec = "0" + sec;
  if (min < 10) dmin = "0" + min;
  if (hou < 10) dhou = "0" + hou;
  if (sec <= 0)
  {
    sec = 59;
    min = min - 1;
    if (min <= 0)
    {
      min = 59;
      hou = hou - 1;
      if (hou <= 0)
      {
        hou = 23;
        day = day - 1;
        if (day <= 0)
        {
          document.getElementById("clock").innerHTML = "";
          exit;
        }
      }
    }
  }
  var text = "" + day + " dni, " + dhou + ":" + dmin + ":" + dsec;
  document.getElementById("clock").innerHTML = text;
  setTimeout("update()",1000);
}

setTimeout("update()",1);