js realizes countdown effect (less than 10 zeros)

Without saying much, please look at the code:

function checkTime(i) {
          if (i<10) {
            i = "0" +i;
          }
          return i;
        };
    function GetRTime(t){
            h=Math.floor(t/60/60);
            m=Math.floor(t/60%60);
            s=Math.floor(t%60);
        d = checkTime(d);
            h = checkTime(h);
            m = checkTime(m);
            s = checkTime(s); 
            $(".hours").val(h);
            $(".minutes").val(m);
            $(".seconds").val(s);
            $(".dot").html(":");
        }