MacBook wont start properly

Hi there..

I tried to find a thread with similar info but could not find.

I was using my macbook 15 inch 2009 and it froze (i was typing an email and had some browser windows open)

I went to restart my computer and when it re-booted it came to the gray screen with the apple and little moving circle and won't move past

I tried taking my battery out and restarting with it just plugged in wall (no help)

and i also did the resetting pram thing.

please help

late for a meeting and need my laptop with me...

okay... update..

also.. it keeps doing the reboot sound every five minutes (with still gray screen) (even when the laptop is shut)