anchor.diff:  
   window.phase = 'sample';
   function sampleOrChooseState(state) {
  -  if (state == 'sample' && ((data.user_ids.length > 1) && data.chosen_buttons.length == data.user_ids.length - 1)) { //last choice
  +
  +  if (state == 'sample' && ((data.user_ids.length > 1) && $(".box").not('.blocked').not('.disabled').length==1)) { //last choice
       alert('The other option was chosen by another player, thus you have to choose the remaining option.')
       return;
     }
  
positive.code:   height: 100%;
    width: 80%;
    opacity: 0.6;
    font-size:20px;
    font-weight: bold;
    background-color: lightgrey;
    z-index: 999;
  
negative.code: 
      window.d = data;
      delete data.rounds_order;
      
      if (localStorage.showData) $('.status').html(JSON.stringify(data))
  
      var highlight = false;    
      var round_num_text = parseInt(data.round)+1;
  