//graph
        private void panel3_Click(object sender, EventArgs e)
        {
            graph_cite lgc = new graph_cite();

            lgc.Update();
            lgc.StartPosition = FormStartPosition.CenterScreen;
            lgc.Show();
            lgc.MdiParent = this;
            lgc_b         = true;
            lgc.Location  = new Point(172, 37);
            frm.Hide();
            prt.Hide();
        }
        //graph icon
        private void pictureBox1_Click(object sender, EventArgs e)
        {
            graph_cite lgc = new graph_cite();

            lgc.Update();
            lgc.StartPosition = FormStartPosition.CenterScreen;
            lgc.Show();
            lgc.MdiParent = this;
            lgc_b         = true;
            lgc.Location  = new Point(61, 40);
            lgc.Size      = new Size(850, 620);
            frm.Hide();
            prt.Hide();
        }