//lay so luong sach nhap trong thang
int GetSLNhap(int thang, int nam, string masach)
{
int soluongnhap = 0;
SachBUS objSach = new SachBUS();
DataTable dtSLNhap = objSach.GetSoLuongNhap(thang, nam, masach);
for (int j = 0; j < dtSLNhap.Rows.Count; j++)
{
soluongnhap += int.Parse(dtSLNhap.Rows[j]["soluong"].ToString());
}
return(soluongnhap);
}