Megane I, 1997 Immo and keys

[johanddrdre]

I recently bought a Megane 1997 cabrio with only the simple keys (without transponder). When I changed my battery, I had to give in a code with the doorlock button to free the immo. I read in some post that normally after some 10 minutes, you have to give in the code again after switching off the ignition. Not in my case. Only when I take off one of the battery connections. So I don't have a problem, but just because I am curious, I would like to know what steps to take to bring everything back to moriginal, including some remote control keys. And ofcourse, I want to do it myslef.

I don't ask you to write down for me the complete procedure (If you want to, you're welcome) but may be some hints or links where to start, or where to start reading.

Thank you.
Johan