how to Display the image in Full screen C#

String imagepath=@"C:\\image1";
  pictureBox1.BorderStyle= BorderStyle.None;
  pictureBox1.Dock=DockSytle.None;
  PictureBox1.Width= this.Width;
  pictureBox1.Height= this.Height;
   pictureBox1.Left= screen.primarySreen.Bounds.width - this .Width;
 pictureBox1.Top= screen.primarySreen.Bounds.Height - this.Height;
  windowstate = FormWindowState.None;
 pictureBox1.Load(imagepath);