private void đăngToolStripMenuItem_Click(object sender, EventArgs e) { if (frmdk == null || frmdk.IsDisposed) { frmdk = new FrmDangKy(); } frmdk.ShowDialog(); }
private void đăngToolStripMenuItem_Click(object sender, EventArgs e) { FrmDangKy frmdk = new FrmDangKy(); frmdk.Show(); }