private void pictureBox1_Click_2(object sender, EventArgs e) { if (pnMain.Controls["CRCafeteria"] == null) { pnMain.Controls.Clear(); CRCafeteria frmcafe = new CRCafeteria(1); frmcafe.TopLevel = false; pnMain.Controls.Add(frmcafe); frmcafe.FormBorderStyle = System.Windows.Forms.FormBorderStyle.None; frmcafe.Dock = DockStyle.Fill; frmcafe.Show(); } }