protected virtual void RenderStyleSheets(HtmlTextWriter writer, StyleFlags flags)
        {
            Queue queue = (Queue)styleFormat;
            if(queue != null && queue.Count > 0)
            {
                IEnumerator ie = queue.GetEnumerator( );
                while(ie.MoveNext())
                {
                    StyleQueue si = (StyleQueue)ie.Current;
                    if (si.position == flags)
                        writer.WriteLine( si.styleTag );
                }
            }
        }