private void btnQLHĐ_Click(object sender, EventArgs e)
{
QuanlyHoadon quanlyHoadon = new QuanlyHoadon();
quanlyHoadon.Show();
}
private void invoicesToolStripMenuItem_Click(object sender, EventArgs e)
{
QuanlyHoadon quanlyHoadon = new QuanlyHoadon();
addForm(quanlyHoadon);
}