How do I connect car stereo to battery?

[KAFKA]

Hi. Since the battery was removed my stereo doesn't work. It doesn't even switch on. I'm guessing that a lead has been connected wrongly somewhere, but not having reconnected the battery myself I have no idea which one. There's a load of leads and I don't know which one's belong to the stereo.

There are a couple of red and black leads going to the + terminal and black ones to the -. The car's an M reg. Fiesta and I think the radio probably came with the car, though this particular madel isn't in the handbook. The model no. is 2015, if this helps.

This is my first car and, as is probably obvious, I'm a complete novice. Anything that might point me in the right direction appreciated. Thanks.

[matt_damon]

Some car stereos are 'security coded' (the unit requires a code number to be keyed in before it functions)... disconnecting the car battery for any reason can result in the stereo becoming 'locked'... the security code needs to be keyed in again before it will work.

[KAFKA]

Thanks Matt. It is a keycode stereo and I have the code, but I need to be able to switch it on in order to enter the code. There's absolutely no power, which makes me think that, if the radio's not faulty, it must be a problem with a connection somewhere.