rover 416 ls radio?

Hi

I have recently inherited a 1998 rover 416

Iwas told a new battery was fitted

However i now cannot use the radio

I need to know how to turn it on please, seems simple but pushing the on button achieves nothing and would anybody know the code for the radio/cassette as well.

Please can you help as i am taking my children for a holiday next week and need the radio

tks
Pat