gistfile1.txt

      // If the model has changed, warn user.
      var formData = mapFormToObject(this.model.schema)
        , newModel = _.extend({}, this.model.attributes, formData)

      if (_.isEqual(this.initialModel, newModel)
        || confirm('You have unsaved changes. Are you sure you want to cancel?')) {
        this.trigger('cancel')
      }