private void hủyCuốnSáchToolStripMenuItem_Click(object sender, EventArgs e) { frmHuyCuonSach a = new frmHuyCuonSach(); a.MdiParent = this; a.Show(); }
private void button1_Click(object sender, EventArgs e) { frmHuyCuonSach a = new frmHuyCuonSach(); a.Show(); }