private void hàngHóaToolStripMenuItem_Click(object sender, EventArgs e) { khachhang frm = new khachhang(); frm.MdiParent = this; frm.Show(); }
private void buttonItem4_Click(object sender, EventArgs e) { khachhang kh = new khachhang(); kh.MdiParent = this; kh.Show(); //this.Hide(); }