anchor.diff:      updateCategory(category);
       resetExpense();
       resetErrors();
  -
  -    var expenses = category.expenses
  -    for (var i = 0; i < expenses.length; i++) {
  -      var expense = expenses[i];
  -      addExpenseRow(expense);
  -    }
  +    fillExpenseTable(category);
     }
   
     function updateCategory(category) {
  
positive.code: 
    function handleExpenseError(error) {
      resetErrors();
      $('#error_message').text("Please enter valid information.");
      errors = JSON.parse(error.responseText).error;
      for (var j = 0; j < errors.length; j++) {
        var error = errors[j];
        $('#error_list').append('<li>' + error + '</li>');
  
negative.code:     $('form')[0].reset();
    }
  
    function fillExpenseTable(category) {
      var expenses = category.expenses
      for (var i = 0; i < expenses.length; i++) {
        var expense = expenses[i];
        addExpenseRow(expense);
      }
    }
  
    function addExpenseRow(expense) {
      var description = '<th scope="row">' + expense.description + '</th>';
      var percentage = '<td>' + expense.percentage() + '%</td>';
  