private void stockToolStripMenuItem_Click(object sender, EventArgs e)
        {
            PStock pro1 = new PStock();

            pro1.MdiParent = this;
            pro1.Show();
        }
        public StockMain()
        {
            InitializeComponent();
            //load stock list at start
            PStock pro1 = new PStock();

            pro1.MdiParent = this;
            pro1.Show();
        }