I have a Macbook (Mac OS X) under a year old, and only for the past two days whenever i close the lid it'd turn off completely then i'd have to turn it on.
But then today the same thing happens however i turn it on and it gets to the log in screen and turns off completley and his happening more than 7 times till it actually works, and then sometimes it'd turn off even when loaded..however this time is is working again.

But i'm sure it'll happen again.

HELP WHAT DO I DO??