anchor.diff:                  Start Discovering Asteroids...&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span class="caret"></span>
                 </button>
                 <ul class="dropdown-menu" role="menu" aria-labelledby="dropdownMenu1">
  -                <li role="presentation"><a role="menuitem" tabindex="-1" href="javascript:danger()">Which asteroids have the highest risk of impacting Earth?"</a></li>
  +                <li role="presentation"><a role="menuitem" tabindex="-1" href="javascript:switchQuestion(1)">Which asteroids have the highest risk of impacting Earth?"</a></li>
                   <li role="presentation" class="divider"></li>
  -                <li role="presentation"><a role="menuitem" tabindex="-1" href="javascript:filter([[3500,10000], null, null, null])">Which are the biggest asteroids?</a></li>
  +                <li role="presentation"><a role="menuitem" tabindex="-1" href="javascript:switchQuestion(2)">Which are the biggest asteroids?</a></li>
                   <li role="presentation" class="divider"></li>
  -                <li role="presentation"><a role="menuitem" tabindex="-1" href="javascript:flyby()">Which asteroids are flying by the earth this month?</a></li>
  +                <li role="presentation"><a role="menuitem" tabindex="-1" href="javascript:switchQuestion(3)">Which asteroids are flying by the earth this month?</a></li>
                   <li role="presentation" class="divider"></li>
  -                <li role="presentation"><a role="menuitem" tabindex="-1" href="javascript:filter([null, null, null, [0.0,4.2]])">Which asteroids are easisest to travel to?</a></li>
  +                <li role="presentation"><a role="menuitem" tabindex="-1" href="javascript:switchQuestion(4)">Which asteroids are easisest to travel to?</a></li>
                 </ul>
               </div>
   
  
positive.code:   // var toggleFlag = 0;
    toggleAsteroidView(0);
  
    <% if @filter_type=="hazard" %>
      // impact2.filterRange([0.00009, 1.0]);
      // window.filter([null,null,null,null]);
      window.danger();
    <% elsif @filter_type=="size"  %>
      window.filter([[3500,10000],null,null,null]);
    <% elsif @filter_type=="near"  %>
      // window.filter([null,[0,20], [0.0,0.7], null]);
      window.flyby();
    <% elsif @filter_type=="easy"  %>
      window.filter([null, null, null, [0.0,4.2]]);
    <% end %> 
    
    // start with showing table list, hiding highchart
    // var toggleFlag = 0;
    // toggleAsteroidView(0);
  
    // renderAll();
  
    // Renders the specified chart or list.
    function render(method) {
      d3.select(this).call(method);
  
negative.code:     var impactSeries = [];
  
      $(function(){
          // seems it remembers the dimension data being fetched already in earlier call.
          var sortedDataSet = null;
          if( asteroidSortingDimension === close_date || asteroidSortingDimension === energy) {
            // ascending
            sortedDataSet = asteroidSortingDimension.bottom(1); 
          } 
          else {
            // descending
            sortedDataSet = asteroidSortingDimension.top(1);
          }
  
          var asteroid = d3.select(this).selectAll(".asteroid")
            .data(sortedDataSet, function(d) { 
  
              var dateStr = d.close_app_date.split(' ');
              var date = Date.UTC(dateStr[0],dateStr[1],dateStr[2]);
  