private void sảnPhẩmToolStripMenuItem_Click(object sender, EventArgs e)
{
QuanLySanPham quanLy = new QuanLySanPham();
quanLy.MdiParent = this;
quanLy.Show();
}
private void btnThemMoiSanPham_Click(object sender, EventArgs e)
{
QuanLySanPham qly = new QuanLySanPham();
qly.ktra = 1;
qly.MdiParent = this.MdiParent;
qly.Show();
}