CD Key?

[XtReMeOnE]

I just bought HL 2 a few hours ago, but I can't find my cd key. I know it sounds retarded, but I have looked alot. Can anyone please tell me where it is? Thanks,
~~X

 

[chriscanadian]

its on the back of one of the CD sleves. It's a sticker.

 

[XtReMeOnE]

Thanks, I guess I looked on most of the cases, but not that one .