oh ok cause kozilek ability says if put into graveyard from anywere shuffle it and graveyard into library. i was told it doesnt even get to the graveyard it was one of the few cards that dont enter the graveyard so cards like undead alchemist couldnt exile it.
First, you can help us help you by utilizing card tags. Putting these [_c_] [_/c_](without the underlines) makes Leyline of the Void into Leyline of the Void. Check the FAQ for more details.
So, Kozilek, Butcher of Truth and Leyline of the Void(I don't think either version of Leyline matters at this point). Ruling for Leyline states, "8/15/2010 Leyline of the Void’s second ability prevents cards from ever reaching your opponents’ graveyards. Abilities that would trigger when those cards are put into an opponent’s graveyard (such as Hoarding Dragon’s last ability) won’t trigger."
So yes, precisely as greywyn said. What you're thinking of is incorrect, and it's worth noting and being keenly aware of, especially in EDH...if Kozilek, Child of Alara or Ulamog, the Infinite Gyre are your commanders and get killed, putting them into your command zone also does not count to activate GY triggers.