anchor.diff:        $(".modal-body").html(purchasesString);
       });
       $(".js-pager").on("click", function() {
  -      nextId--;
  -      $.get("/plans/" + nextId + ".json", function(data) {
  -        var date = new Date(data["date"]);
  -        var month = [];
  -        month[0] = "January";
  -        month[1] = "February";
  -        month[2] = "March";
  -        month[3] = "April";
  -        month[4] = "May";
  -        month[5] = "June";
  -        month[6] = "July";
  -        month[7] = "August";
  -        month[8] = "September";
  -        month[9] = "October";
  -        month[10] = "November";
  -        month[11] = "December";
  -        $(".modal-title").text(`In ${month[date.getMonth()]} you budgeted...`);
  -
  -        var purchases = data["purchases"];
  -        var purchasesString = "";
  -        $.each(purchases, function(i, purchase) {
  -          purchasesString += `<p data-paymentid="${purchase["id"]}">` + "$" + `${purchase["price"]} ` + "for " + `${purchase["item"]} ` + "</p>";
  +      if (numberOfPastPlans === 0) {
  +        $("#myModal").modal('hide');
  +      } else {
  +        numberOfPastPlans--;
  +        nextId--;
  +        $.get("/plans/" + nextId + ".json", function(data) {
  +          var date = new Date(data["date"]);
  +          var month = [];
  +          month[0] = "January";
  +          month[1] = "February";
  +          month[2] = "March";
  +          month[3] = "April";
  +          month[4] = "May";
  +          month[5] = "June";
  +          month[6] = "July";
  +          month[7] = "August";
  +          month[8] = "September";
  +          month[9] = "October";
  +          month[10] = "November";
  +          month[11] = "December";
  +          $(".modal-title").text(`In ${month[date.getMonth()]} you budgeted...`);
  +          var purchases = data["purchases"];
  +          var purchasesString = "";
  +          $.each(purchases, function(i, purchase) {
  +            purchasesString += `<p data-paymentid="${purchase["id"]}">` + "$" + `${purchase["price"]} ` + "for " + `${purchase["item"]} ` + "</p>";
  +          });
  +          $(".modal-body").html(purchasesString);
           });
  -        $(".modal-body").html(purchasesString);
  -      });
  +      }
       });
     });
   });
  
positive.code:         ...
        </div>
        <div class="modal-footer">
          <button type="button" class="btn btn-primary js-pager" data-id="<%= @plan.id %>">Previous</button>
          <button type="button" class="btn btn-default" data-dismiss="modal">Close</button>
        </div>
      </div>
  
negative.code: $(function () {
    $(".js-previous").on("click", function() {
      var nextId = parseInt($(".js-previous").attr("data-id")) - 1;
      var numberOfPastPlans = parseInt($(".js-pager").attr("data-count")) - 1;
      $.get("/plans/" + nextId + ".json", function(data) {
        var date = new Date(data["date"]);
        var month = [];
  