function addOrder() {
          var orderTextBox = document.getElementById('order');         
          var orderText = orderTextBox.value;
          orderTextBox.value = "";
          
          var newOrder = document.createElement('li');
          var newOrderText = document.createTextNode(orderText);
          newOrder.appendChild(newOrderText);   
                                           
          var orderList = document.getElementById('order_list');
          orderList.appendChild(newOrder);
  }