Does any one know much about the keys for Ford Focus.

My sister has recently bought a 2000 Focus Zetec and it only came with one remote key fob. The key works perfectly however the remote central locking part doesn't. So I've had a quick look on the interweb and you can pick up new keys quite cheaply, however upon reading several websites about Ford keys it appears to can't programme in a new key without the master blue key, which my sister doesn't have.

Looking into it a bit further this is only the case when programming a new key to start the car. If you just want to programme a new central locking remote, you can do this with any key. Can anyone confirm this?

We can worry about getting a new master key at a later date, it's just the remote central locking fob she wants to get working at the moment.

Thanks.