var Rotator = Class.create();
Rotator.prototype = {
    initialize: function(div_name, count, interval) {
        this.div_name = div_name;
        this.count = count;
        this.interval = interval;
        this.active = 1;
        this.start();
      },
      
    start: function() {
        this.timer = setInterval(this.onTimerEvent.bind(this), this.interval * 1000);
    },
    
    onTimerEvent: function() {
        from = this.active;
        if (this.active == this.count) {
          this.active = 1;
        } else {
          this.active++;
        }
        to = this.active;
          
        Effect.Fade(this.div_name + "_" + from);
        Effect.Appear(this.div_name + "_" + to);
    },
    
    feature: function(panel) {
       if (this.timer != 0) {
           clearInterval(this.timer)
           this.timer = 0
       }
       if (panel != this.active) {
           Effect.Fade(this.div_name + "_" + this.active);
           this.active = panel;
           Effect.Appear(this.div_name + "_" + this.active);
       }
    }
}