Škoda Octavia key fob battery

 The car told me to replace the battery in the keyfob.  I did and it didn't work.  I put the old battery back in and it didn't work.  Not even the flashing light on the keyfob itself.

I read on "the internet" that someone had had a similar problem and the fob needed a Panasonic battery.  I was very sceptical but bought some Panasonics.  It worked!