private void DanToc_Click_1(object sender, EventArgs e) { if (DanTocfrm == null || DanTocfrm.IsDisposed) { DanTocfrm = new frmDanToc(); DanTocfrm.MdiParent = this; DanTocfrm.Show(); } else { DanTocfrm.Activate(); } }
private void ThemDanToc_Click(object sender, EventArgs e) { frmDanToc DT = new frmDanToc(); DT.ShowDialog(); }