Create Rounded corner Form in C#.Net

From various source on the net

protected override void OnPaint(PaintEventArgs e)
{
//base.OnPaint (e);
GraphicsPath p = new GraphicsPath();
p.StartFigure();
p.AddArc(new Rectangle(0, 0, 40, 40), 180, 90);
p.AddLine(40, 0, this.Width - 40, 0);
p.AddArc(new Rectangle(this.Width - 40, 0, 40, 40), -90, 90);
p.AddLine(this.Width, 40, this.Width , this.Height - 40);
p.AddArc(new Rectangle(this.Width - 40, this.Height - 40, 40, 40), 0, 90);
p.AddLine(this.Width - 40, this.Height, 40, this.Height);
p.AddArc(new Rectangle(0, this.Height - 40 , 40, 40), 90, 90);
p.CloseFigure();
this.Region = new Region(p);

SolidBrush oBlackBrush = new SolidBrush(System.Drawing.Color.Black);
System.Drawing.Pen borderPen = new System.Drawing.Pen(oBlackBrush, 4);
e.Graphics.DrawPath(borderPen, p);
borderPen.Dispose();

p.Dispose();
}