log([e.html(), correct_text]); button_state = 1.0; console.log(['click-button', button_state, link_state]); })
      }
    } else {
      e.on('click', function(){ console.log([e.html(), correct_text]); button_state = -1.0; console.log(['click-button', button_state, link_state]); })
    }
  }

  // click-checkboxes
  var box_state = -1.0;
  var div = d3.select('#area');
  var boxesDiv = $('#boxes');
  if (boxesDiv.length == 0){
    div.append('div').attr('id', 'boxes');
    div.append('br');
    div.append(