anchor.diff:          dataProjectUrl,
           dataExperimentUrl,
           dataSampleUrl,
  -        dataMenuItemsUrl;
  +        dataMenuItemsUrl,
  +        prevAt,
  +        DEFAULT_SEARCH_FILTER;
   
       dataUserUrl = $(document.body).attr('data-atwho-users-url');
       dataTaskUrl = $(document.body).attr('data-atwho-task-url');
  
positive.code:         acceptSpaceBar: true,
          displayTimeout: 120000
        })
        .atwho({
          at: '#',
          callbacks: {
            remoteFilter: function(query, callback) {
              var searchFilter = $('.atwho-view[style] .btn-primary').data('filter');
              if (_.isUndefined(searchFilter)) {
                searchFilter = DEFAULT_SEARCH_FILTER;
              }
  
              var dataUrl;
              switch(searchFilter) {
                  case 'tsk':
                      dataUrl = dataTaskUrl;
                      break;
                  case 'prj':
                      dataUrl = dataProjectUrl;
                      break;
                  case 'exp':
                      dataUrl = dataExperimentUrl;
                      break;
                  case 'sam':
                      dataUrl = dataSampleUrl;
                      break;
              }
  
              $.getJSON(
                dataUrl,
                {query: query},
                function(data) {
                  callback(data.res);
                  initButtons(query, searchFilter);
                }
              );
            },
            tplEval: function(_tpl, map) {
              return _templateEval(_tpl, map);
            },
            highlighter:  function(li, query) {
              return _matchHighlighter(li, query, true);
            },
            beforeInsert: function(value, li) {
              return _generateInputTag(value, li);
            }
          },
          headerTpl: generateFilterMenu(DEFAULT_SEARCH_FILTER),
          limit: <%= Constants::ATWHO_SEARCH_LIMIT %>,
          startWithSpace: true,
          acceptSpaceBar: true,
          displayTimeout: 120000
        })
        .atwho({
          at: 'task#',
          callbacks: {
            remoteFilter: function(query, callback) {
              $.getJSON(
                dataTaskUrl,
                {query: query},
                function(data) {
                  callback(data.res);
                  initButtons(query, 'tsk');
                }
              );
            },
            tplEval: function(_tpl, map) {
              return _templateEval(_tpl, map);
            },
            highlighter: function(li, query) {
              return _matchHighlighter(li, query, true);
            },
            beforeInsert: function(value, li) {
              return _generateInputTag(value, li);
            }
          },
          headerTpl: generateFilterMenu('tsk'),
          limit: <%= Constants::ATWHO_SEARCH_LIMIT %>,
          startWithSpace: true,
          acceptSpaceBar: true,
          displayTimeout: 120000
        })
        .atwho({
          at: 'project#',
          callbacks: {
            remoteFilter: function(query, callback) {
              $.getJSON(
                dataProjectUrl,
                {query: query},
                function(data) {
                  callback(data.res);
                  initButtons(query, 'prj');
                }
              );
            },
            tplEval: function(_tpl, map) {
              return _templateEval(_tpl, map);
            },
            highlighter: function(li, query) {
              return _matchHighlighter(li, query, true);
            },
            beforeInsert: function(value, li) {
              return _generateInputTag(value, li);
            }
          },
          headerTpl: generateFilterMenu('prj'),
          limit: <%= Constants::ATWHO_SEARCH_LIMIT %>,
          startWithSpace: true,
          acceptSpaceBar: true,
          displayTimeout: 120000
        })
        .atwho({
          at: 'experiment#',
          callbacks: {
            remoteFilter: function(query, callback) {
              $.getJSON(
                dataExperimentUrl,
                {query: query},
                function(data) {
                  callback(data.res);
                  initButtons(query, 'exp');
                }
              );
            },
            tplEval: function(_tpl, map) {
              return _templateEval(_tpl, map);
            },
            highlighter: function(li, query) {
              return _matchHighlighter(li, query, true);
            },
            beforeInsert: function(value, li) {
              return _generateInputTag(value, li);
            }
          },
          headerTpl: generateFilterMenu('exp'),
          limit: <%= Constants::ATWHO_SEARCH_LIMIT %>,
          startWithSpace: true,
          acceptSpaceBar: true,
          displayTimeout: 120000
        })
        .atwho({
          at: 'sample#',
          callbacks: {
            remoteFilter: function(query, callback) {
              $.getJSON(
                dataSampleUrl,
                {query: query},
                function(data) {
                  callback(data.res);
                  initButtons(query, 'sam');
                }
              );
            },
            tplEval: function(_tpl, map) {
              return _templateEval(_tpl, map);
            },
            highlighter: function(li, query) {
              return _matchHighlighter(li, query, true);
            },
            beforeInsert: function(value, li) {
              return _generateInputTag(value, li);
            }
          },
          headerTpl: generateFilterMenu('sam'),
          limit: <%= Constants::ATWHO_SEARCH_LIMIT %>,
          startWithSpace: true,
          acceptSpaceBar: true,
          displayTimeout: 120000
        });
      }
  
      return {
  
negative.code:     dataExperimentUrl = $(document.body).attr('data-atwho-experiment-url');
      dataSampleUrl = $(document.body).attr('data-atwho-sample-url');
      dataMenuItemsUrl = $(document.body).attr('data-atwho-menu-items');
      // Default selected filter when using '#'
      DEFAULT_SEARCH_FILTER = 'sam';
  
      // helper methods for AtWho callback
      function _templateEval(_tpl, map) {
  