private void cbbMaDoan_SelectedIndexChanged(object sender, EventArgs e)
{
if (cbbMaDoan.SelectedIndex == 0)
{
dataGridView1.DataSource = bus1.ThongKeChiPhiTatCaDoanTheoTour(ma, dateTimePicker1.Text, dateTimePicker2.Text);
}
else
{
string madoan = cbbMaDoan.Text;
dataGridView1.DataSource = bus1.ThongKeChiPhiTatCaDoanTheoTourCoMaDoan(ma, dateTimePicker1.Text, dateTimePicker2.Text, madoan);
}
}