won't turn on and does a beeping soung instead

Hi there, I had some problem with my macbook pro a while back, in which the screen was getting blank/frozen and I had to force quit it, and when i tried to turn it back on, it started beeping and would not turn on...then I would wait some hours and it would finally turn on. It was acting like this for a while and I managed to fix it by repairing the disk in disk utility and it was working fine...

Now, since yesterday, it started again, and i had to force quit it, but this time, it is not turning on at all anymore, and it only does the beeping sound when I try to turn it on...firts it does one beeping at a time, and then I force quit it again and turn it on again and it does a faster beeping sequence.

Can anyone help me?

my mac info is:

Mac OS X

version 10.6.8

2.4 GHz Intel Core 2 Duo

4 GB 1067 Mhz DDR3

I never did any work on it, never changed anything...it is just like I got it from the shop.

Thanks