2001 Renault Megane Immobiliser Code & Problem?

Hi all, I have 2001, Y Reg Renault Meagane Scenic Expression 1.6 Litre.
I have a problem whereby it won't start and the ECU isn't sending a feed out. Had the ECU checked by a company and it works fine, which can only leave the immobiliser I believe.
I have reset the keys and the locking works finem but on checking the inside of the keys there is no immobiliser code.

Does anyone how I can get these details or how I can obtain the security bypass code and where from so that I can see if this is the problem.

Any help would be apprieciated.

Thanks,

Nick.
January 2011