var Countdown = new function(mins, seconds, done) {
   this.timeLeft = mins * 60 + seconds;
   this.done = done;
}

Countdown.prototype.start = function () {
   var self = this;
   var down = function () {
       this.countdown--;
       if(self.timeLeft > 0) {
           self.counter = setTimeout(down, 1000);
       } else {
           self.done();
       }
   };
}

Countdown.prototype.pause = function () {
    if ( this.counter) {
        clearTimeout(this.counter); 
    }
}

Countdown.prototype.reset = function () {
    this.timeLeft = 0;
    if ( this.counter) {
        clearTimeout(this.counter); 
    }
}

// global
var c;

// in widget create
var c = new Countdown(minutes, seconds);

// on start
c.start();

// pause
c.pause();

//reset
c.reset();