void OnPredefinedBorderComboSelectedIndexChanged(NValueChangeEventArgs args)
        {
            if (m_PredefinedBorderCombo.SelectedIndex == -1)
            {
                return;
            }

            double innerRadius = m_InnerRadiusCombo.SelectedIndex;
            double outerRadius = m_OuterRadiusCombo.SelectedIndex;

            // apply a predefined border
            NCustomBorderWallWidget[] elements = GetCustomBorderElements();
            for (int i = 0; i < elements.Length; i++)
            {
                NBorder border = null;
                switch (m_PredefinedBorderCombo.SelectedIndex)
                {
                case 0:     // 3D Raised Border
                    border = NBorder.CreateRaised3DBorder(new NUIThemeColorMap(ENUIThemeScheme.WindowsClassic));
                    break;

                case 1:     // 3D Sunken Border
                    border = NBorder.CreateSunken3DBorder(new NUIThemeColorMap(ENUIThemeScheme.WindowsClassic));
                    break;

                case 2:     // Filled Border
                    border = NBorder.CreateFilledBorder(NColor.Red);
                    break;

                case 3:     // Filled Border with Outlines
                    border = NBorder.CreateFilledBorder(new NColorFill(NColor.Blue), new NStroke(1, NColor.Black), new NStroke(1, NColor.Black));
                    break;
                }

                border.SetRadiuses(innerRadius, outerRadius);
                elements[i].Border = border;
            }
        }