text: $(document).ready(function() {
    $("form#numbers").submit(function(event){
  
      var countUntil = parseInt($("#count-until").val());
      var countBy = parseInt($("#count-by").val());
  
      var array = [];
  
      if (countUntil < 0 || countBy < 0) {
        alert("Please use only positive numbers");
      } else if (countUntil < countBy){
        alert ("The number you'll count until should be bigger than the number you'll count by.");
      } else {
        for (var i = countBy; i <= countUntil; i += countBy) {
          array.push(i);
          var stringResult = array.join(", ");
          $("#display-count-to").text(countUntil);
          $("#display-count-by").text(countBy);
          $("#display-output").text(stringResult);
          $(".display-result").show();
        };
      }
  
      event.preventDefault();
  
    });
  });
  