protected void Window_Paint(object sender, PaintEventArgs e)
{
Graphics g = e.Graphics;
g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias;
UserGraphics ug=new UserGraphics(g);
Pen pen=new Pen(Color.Gray,2);
Brush brush = new SolidBrush(Color.Black);
ug.FillArcRadius(brush, 0, 21, this.Width-1, this.Height-22, 5);
ug.DrawArcRadius(pen, 2, 23, this.Width - 6, this.Height - 27, 5);
}