private void timer1_Tick(object sender, EventArgs e)
    {
        pictureBox1.Location = new Point(pictureBox1.Location.X - 1, pictureBox1.Location.Y);

        //if (pictureBox1.Location.X == -713)
        //{
        //    pictureBox1.Location = new Point(713, pictureBox1.Location.Y);
        //}
    }