ZoneUpdater - jQuery edition

I recently started using the excellent tapestry-jquery plugin that replaces prototype in T5. The internal implementation of zones in tapestry changes quite a bit in tapestry-jquery, so I had to change a couple of things in ZoneUpdater too. I find the updated code to be quite a bit better, here it is:

var ZoneUpdater = function(spec) {

 var elementId = spec.elementId;
 var element = document.getElementById(elementId);
 var url = spec.url;
 var $zone = jQuery('#' + spec.zone);

 var updateZone = function() {
  var updatedUrl = url;
  var params = {};  
  if (element.value) {
   params.param = element.value;
  }
  $zone.tapestryZone('update', {
   url : updatedUrl, 
   params : params
  });
 }
 
 if (spec.event) {
  var event = spec.event;
  jQuery(element).bind(event, updateZone);
 }


 return {
  updateZone : updateZone
 };
}