text: let hour,min,sec,ms,count, malt, salt, msalt;
  
  class Stopwatch{
      constructor(){
          this.count;
      };
      stop() {
          if (this.count) {
              clearInterval(this.count);
              this.count = null;
          }
      }
  
      start(){
          let update = function(txt){
              let  temp = document.getElementById("timer");
              temp.firstChild.nodeValue = txt;
          }
         let pad =  function(time){
              let  temp;
              if(time < 10){
                  temp = "0" + time;
              }
              else{
                  temp = time;
              }
              return temp;
          }
          // if(document.getElementById("start").firstChild.nodeValue !== "Start"){
          //     document.getElementById("start").firstChild.nodeValue = "Start";
          // }
          if(!this.count){
              ms = 0;
              sec = 0;
              min = 0;
              hour = 0;
              this.count = setInterval(function(){
                  if(min==60){
                      min=0;
                      hour++;
                  }
                  if(ms == 100){
                      ms = 0;
                      if(sec == 60){
                          sec = 0;
                          min++;
                      }
                      else{
                          sec++;
                      }
                  }
                  else{
                      ms++;
                  }
  
                  let halt = pad(hour);
                  let malt = pad(min);
                  let salt = pad(sec);
                  let msalt = pad(ms);
  
  
                  update( malt + ":" + salt );
              }, 10);
          }
  
  
      }
  
  }
  
  window.StopwatchFactory = {
  
      Stopwatch: Stopwatch
  };