How to play online(what crack and patch is needed for it)

hi,
ive downloaded crysis 2 yesterday and i dnt know how to play online....i followed most of the tutorials from youtube but im getting a serial code invalid error...and i cant understand the tutorials over here...pls help me...and also tell me which patch and crack i need...pls help me...pls help me...

It is difficult to play Crysis 2 Multiplayer these days. The CRYTEK guys have made many improvements agains this.

However you can sill play but in a specified time!
You must fins that specified time!