battery problems

Hi everybody.

i have a macbook and the battery doesnt seem to be holding charge anymore. if i had to remove the power supply while its on it would just switch off.
Could it be something else, or do i just need to buy a new battery?

thanks
nick

go to apple-> about this mac-> click more info
click power under hardware.
Check out how the battery is doing. there is a cut off of how many charge cycles a batter should last. ~350 or something. If it dies too quick they might replace it with apple care else you need a new one.