public string doanhThuTheoNgay(string ngay)
{
DataTable infotable = hd.doanhThuTheoNgay(ngay);
if (infotable.Rows.Count == 0)
{
return("0");
}
return(((long)double.Parse(infotable.Rows[0].ItemArray[0].ToString())).ToString("0,000"));
}