private void Form1_Load(object sender, System.EventArgs e)
		{
			SetStyle(ControlStyles.ResizeRedraw, true);
		}
		...
		private void p1_Paint(object sender, System.Windows.Forms.PaintEventArgs e)
		{
			Graphics g = e.Graphics;
			g.DrawLine(Pens.White, 0, 0, p1.Width, 0);
			g.DrawLine(Pens.White, 0, 0, 0, p1.Height);

			g.DrawLine(Pens.Gray, 1, p1.Height-1, p1.Width-2, p1.Height - 1);
			g.DrawLine(Pens.Gray, p1.Width - 1, 1, p1.Width-1, p1.Height - 2);
		}