Here's the story, today I brought 3 games, the Witcher 2 which I'm currently patching, A pre-owned copy of Alpha protocol(Xbox 360 version) and Diablo 2: gold edition but It's Cd key was missing, i could't find it and it was a fresh copy no scratches but it has no cd key in it, the sticker in the box that should have the cd key is gone.

If you are wondering where I brought the game, it was Ebgames Australia which is more infamous.

So can anyone here help me

I got 2 possible options:
1. The CD-Key is somewhere hidden in the manual(happened to me with some other games). Just search every corner of the box.
2. Go to the Blizzard page and register yourself a BNET account. There is a option to register your game. You do not need the CD-KEY to register the games(AFAIK) but the Product Code, which is found on the bottom of the rear of the Product. After registering the game, you can Download a digital version there - also the Key should be mentioned on your registered games page.

Hope some of this helps!

Usually the CD key sticker was plastered on the disc sleeves.

My copy had the sticker behind the discs, was also very confused until I removed the form the box and saw the key.

My cd key was on the cd case on the inside behind the cd

Mine was stickied inside the DVD box. How long ago did you buy it?

Well, the only rescue for you might be e-mailing Blizzard with photos of your box, maybe they will provide you with keys, but I wouldn't expect that.

I brought all three games game Today anyway.

So you should return them to the shop and ask for a new copy ;)