updater = Class.create();  
   updater.prototype = {  
       initialize: function(divToUpdate, interval, file) {  
           this.divToUpdate = divToUpdate;  
           this.interval = interval;  
           this.file = file;  
             
           new PeriodicalExecuter(this.getUpdate.bindAsEventListener(this), this.interval);  
       },  
         
       getUpdate: function() {  
           var oOptions = {  
               method: "POST",  
               asynchronous: true,  
               parameters: "intervalPeriod="+this.interval,  
               onComplete: function (oXHR, Json) {  
                   $(this.divToUpdate).innerHTML = oXHR.responseText;  
               }  
           };  
           var oRequest = new Ajax.Updater(this.divToUpdate, this.file, oOptions);  
       }  
  }