Unobtrusively observe a form with prototype

unobtrusive_observe_form.js

var ObserveForm = Class.create({                                                                                                         
  initialize: function() {
    this.form = $('form_id');  
    this.form.observe('submit', this.submitForm.bindAsEventListener(this));
    this.data_area = $('display_area'); 
  },

  submitForm: function(event) {
    event.stop();
    this.form.request({        
      onSuccess: this.itemCreated.bindAsEventListener(this)
    });
  },

  itemCreated: function(transport) {
    this.data_area.insert({top: transport.responseText});
    this.form.reset();         
  } 
});