internal void OnRender(ITabPanel panel, int currentTabLen, int indent, int index)
            {
                Point point;
                int   curPosition = index * (currentTabLen + indent);

                switch (Orientation)
                {
                case Orientation.Horizontal:
                    point = new Point(curPosition, FixedPoint);
                    panel.ChangeLocation(point);
                    break;

                case Orientation.Vertical:
                    point = new Point(FixedPoint, curPosition);
                    panel.ChangeLocation(point);
                    break;
                }
            }
            private void ChangeLocationHeight(ITabPanel control, int distention)
            {
                Point point = new Point(FixedPoint, distention);

                control.ChangeLocation(point);
            }
            private void ChangeLocationWidth(ITabPanel control, int distention)
            {
                Point point = new Point(distention, FixedPoint);

                control.ChangeLocation(point);
            }