setInterval指针最大值和指针重置

Question

通过setInterval（）在网页上使用多个计时器，并将为每个计时器生成的唯一指针存储在数组中。在每次AJAX调用时，数组都会刷新，指针编号也会增加。我的问题是：使用seInterval / setTimeout可以使javascript指针达到的最大数量是多少，有没有办法将指针数量重置为0？

function countdown(elem,timeToGo,index){
      var cdelem = document.getElementById(elem);
      var interval = setInterval(function(){
      var now = new Date().getTime();
       if (timeToGo<=now){
        cdelem.innerHTML = "fishished";
        clearInterval(tmrsArray[index]);
        }
       else{
        var ttl = timeToGo-now;
        var millisecs = parseInt((ttl%1000)/100),
         secs = parseInt((ttl/1000)%60),
         mins = parseInt((ttl/(1000*60))%60),
         hrs = parseInt((ttl/(1000*60*60))%24);
         hrs = (hrs<10)?"0"+hrs:hrs;
         mins = (mins<10)?"0"+mins:mins;
         secs = (secs<10)?"0"+secs:secs;
        cdelem.innerHTML = hrs+":"+mins+":"+secs;
        }
       }, 1000);
      tmrsArray[index]=interval;
      }