Hibernate in windows vista

How to hybernate in windows Vista. Yeh it was a good option in widows xp. we can hybernate windows xp and wow it was fast. Where did that option goes in vista. Well it is quite simple. No need to waste time to search option to hybernate or activate it just by going in registeries. VISTA merged the hibernation with sleep . Yeh its true try doing it and it works as hibernate does