Windows XP Service Pack 2 Product Key

I have an original cd of Windows XP Service Pack 2, 2002 Version with code
0504 Product Number X10-59871. My problem is my missing product key number. I
don't know if I can be helped out with another product key number or else the
CD would be useless. Thank you very I much if I would be provided with
another that will work with my Win Xp OS software.