var timerID = 0;
var tStart  = null;
var count_time  = 0;

function UpdateTimer() {
  var total_secs = document.getElementById("total_secs").innerHTML;
  count_time = count_time + 1;
  time_left = total_secs - count_time + 1;
  
  if (time_left <= 0) {
    document.frmTimer.submit();
  }
  else {
  
   if(timerID) {
      clearTimeout(timerID);
      clockID  = 0;
   }

   if(!tStart)
      tStart   = new Date();

   var   tDate = new Date();
   var   tDiff = tDate.getTime() - tStart.getTime();

   tDate.setTime(tDiff);

   document.getElementById("timer_secs").innerHTML =  time_left;
   
   timerID = setTimeout("UpdateTimer()", 1000);
  }
}

function ToggleTimer(bShowOptions) {
  btn = document.frmTimer.btnTimer;
   
  if (btn.value == "Start") {
    btn.value = "Freeze";
    document.getElementById("timer_options").style.display = "none";     
    
    document.getElementById("total_secs").innerHTML = document.getElementById("refresh_every").value;
    document.getElementById("timer_secs").innerHTML = document.getElementById("refresh_every").value;
    document.getElementById("t").value ="Y";
    
    StartTimer();    
  }
  else {
    btn.value = "Start";   
    
    if (bShowOptions) {
      document.getElementById("timer_options").style.display = "block";
    }

    StopTimer();
  }
}

function StartTimer() {
  tStart   = new Date();
  timerID  = setTimeout("UpdateTimer()", 1000);  
}  

function StopTimer() {
  if(timerID) {
    clearTimeout(timerID);
    timerID  = 0;
    count_time = 0;
  }
  tStart = null;   
}