I am assuming that the clicking is when you turn the key, it just clicks instead of starting. This would be because the battery hasn't got the guts to turn the engine over.
Get the battery charged, and then take it into a local Motorist Discount Centre, or similar, they can do a load test on it to see if it's holding a charge.
Also, when the car is running, put a multimetre on the battery terminals and you should see about 14.4v. Having said that, they can test this when they do the above.
Let us know how you get on.
Thanks
Mike