var updater = Class.create({  
 initialize: function(divToUpdate, interval, file) {  
this.divToUpdate = divToUpdate;  
this.interval = interval;  
 this.file = file;  
new PeriodicalExecuter(this.getUpdate.bind(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);  
 }  
});