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 currentDate = new Date();
  
      var day = currentDate.getDate();
      var month = currentDate.getMonth();
      var year = currentDate.getFullYear();
  
      var date1 = Date.UTC(year,month, day);
      //var date2 = Date.UTC(year, month+1, day);
      var date2 = date1 + 2592000000;  // milliseconds for 30 days
  
negative.code:     //   date.exit().remove();
  
      div.each(function() {
        var sortedDataSet = null;
        if( asteroidSortingDimension === close_date || asteroidSortingDimension === energy) {
          // ascending
          sortedDataSet = asteroidSortingDimension.bottom(20); 
        } 
        else {
          //descending
          sortedDataSet = asteroidSortingDimension.top(20);
        }
  
        var asteroid = d3.select(this).selectAll(".asteroid")
            .data(sortedDataSet, function(d) { 
                return d.index; 
            });
  
  