C# Bubble sort

 public void BubbleSort()
        {
            DoubleLink lastEnd = new DoubleLink();
            while (lastEnd != null)
            {
                Boolean swapped = false;
                DoubleLink link = First;
                while (link !=null){
                    if (link == Last || link == lastEnd)
                    {
                        lastEnd = link;
                        break;
                    }
                    if (link.Naw.CompareTo(link.Next.Naw) == 1)
                    {
                        SwapLinkWithNext(link);
                        swapped = true;
                    }
                    link = link.Next;
                }
                if (swapped == false )
                {
                    break;
                }
            }
        }