new public void Insert(int index, IndexField val)
		{
			if (this._index != null) 
			{
				val.SetIndex(this._index);
			}
			if ( this.Contains(val) ) 
			{
				this.Remove(val);
			}
			this.Insert(index, val);
		}
		new public int Add(IndexField val)
		{
			if (this._index != null) 
			{
				val.SetIndex(this._index);
			}
			if ( !this.Contains(val) ) 
			{
				return base.Add(val);
			}
			return -1;
		}