private void tsmiQuanLyHoaDonBanHang_Click(object sender, EventArgs e)
{
if (frmBanHang == null || frmBanHang.IsDisposed)
{
frmBanHang = new BanHang();
frmBanHang.MdiParent = this;
frmBanHang.setSelectedTab(1);
frmBanHang.Show();
}
frmBanHang.BringToFront();
}
public FormSuaHoaDonBan(BanHang f)
{
InitializeComponent();
parent = f;
}