public Form1()
        {
            InitializeComponent();

            FileName       = null;
            DoubleBuffered = true;
            thickCount     = 0;
            ballDoc        = new BallDoc(this.Width);
            Timer          = new Timer();
            Timer.Enabled  = true;
            Timer.Interval = 200;
            Timer.Tick    += new EventHandler(this.Thick);
            Timer.Start();
            this.Paint      += new PaintEventHandler(this.Paint_Form);
            this.MouseClick += new MouseEventHandler(this.Mouse_Click);
        }
        private void openToolStripMenuItem_Click(object sender, EventArgs e)
        {
            FileName = null;
            OpenFileDialog op = new OpenFileDialog();

            if (op.ShowDialog() == DialogResult.OK)
            {
                FileName = op.FileName;
            }
            if (FileName != null)
            {
                System.Runtime.Serialization.IFormatter formatter = new System.Runtime.Serialization.
                                                                    Formatters.Binary.BinaryFormatter();
                FileStream str = new FileStream(FileName, FileMode.Open);
                ballDoc = (BallDoc)formatter.Deserialize(str);
                str.Close();
            }
        }