anchor.diff:              var sectionHash = Form.serializeElements(this.formElementsInSection(container), true);
               this._updateContent(container, url, paramHash.merge(sectionHash), function (transport) {
               }.bind(this));
  +
  +            if (itemType == 'agent') $('btn-add-agent').show();
           },
   
           _updateContent: function(container, url, params, onSuccessCallBack) {
  
positive.code:     
      <c:if test="${hasAgent}">
          <chrome:box title="Agent" collapsable="true">
              <jsp:attribute name="additionalTitle"><input type="button" value="Add Agent" id="btn-add-agent"></jsp:attribute>
              <jsp:body>
                  <div style="padding-left:20px;">
                  <div id="_agents">
  
negative.code:         if ($('btn-add-agent'))
              Element.observe('btn-add-agent', 'click', function(e) {
                  this._addItem('agent', e.element(), null, '_agents');
                  $('btn-add-agent').hide();
              }.bind(interventionInstance));
  
          refreshBoxes();
  