Macbook Pro Early 2008 (Not Working) HELP!!

Hi I have a 15" Macbook Pro from early 2008 the A1260 model, the other day I was using it and it was fine then when i came to use it the next day it failed to turn on, so I put it on charge, when its connected to the mains the light on the magsafe turns green but the battery has no lights on it when I press the button on the bottom, the charger definitely works as I tried it on another of my friends Macbooks.

On pressing the on button on the Macbook nothing happens no lights no sounds, nothing. Can anyone help it would be much appreciated.

I have tried resetting the SMC but this has not worked.

Thank you
JAMI3

If you can still turn on the notebook and use it with the magsafe plugged in, it would probably the problem with battery.

No I am unable to turn the system on even with mains adapter connected.