anchor.diff:          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();
  
positive.code:             var sectionHash = Form.serializeElements(this.formElementsInSection(container), true);
              this._updateContent(container, url, paramHash.merge(sectionHash), function (transport) {
              }.bind(this));
          },
  
          _updateContent: function(container, url, params, onSuccessCallBack) {
  
negative.code:     
      <c:if test="${hasAgent}">
          <chrome:box title="Agent" collapsable="true">
              <jsp:attribute name="additionalTitle">
                      <input type="button" value="Add Agent" id="btn-add-agent" style="display:<c:if test="${fn:length(command.aeReport.treatmentInformation.courseAgents) > 0}">none</c:if>">
              </jsp:attribute>
              <jsp:body>
                  <div style="padding-left:20px;">
                  <div id="_agents">
  