protected override void OnPaint( PaintEventArgs e )
{
base.OnPaint( e );
Pen P = Enabled ? Pens.Black : SystemPens.ControlLight;
e.Graphics.DrawLine( P, 0.5f * Width, 0, 0.5f * Width, Height );
e.Graphics.DrawLine( P, 0, 0.5f * (Height-1), 0.5f * Width, 0.5f * (Height-1) );
for ( int i=0; i < m_ChildrenCount; i++ )
e.Graphics.DrawLine( P, 0.5f * Width, (float) i / (m_ChildrenCount-1) * (Height-1), Width, (float) i / (m_ChildrenCount-1) * (Height-1) );
}