anchor.diff:    return 0;
   }
   
  -var preview = false;
  +var is_preview = false;
   function update_data() {
     hide_percent();
     total_amount = 0;
  
positive.code:   .attr("font-size", "1.5em")
    .attr("fill", "gray");
  svg.append("g")
    .attr("class", "preview");
  
  var color = d3.scale.category20();
  
  
negative.code:   data.sort(compare_categories);
  
    /* ------- PREVIEW IF NO DATA -------*/
    if (expenses.length == 0) {
      is_preview = true;
      data = [
        {amount:165.34, category:"Groceries", amount_str:"$165.34"},
        {amount:110.07, category:"Bills",     amount_str:"$110.07"},
  