@EventHandler
	public void oDE(EntityDamageByEntityEvent e) {

		if(e.getEntity() instanceof Player && e.getDamager() instanceof Player) {
			Player p2 = (Player) e.getEntity();
			Player p1 = (Player) e.getDamager();


	if(p2.getInventory().getHelmet().getType() != null){

		p2.sendMessage("youre itttt");
		ItemStack arp1 = p1.getInventory().getHelmet();
    	p2.getInventory().setHelmet(arp1);
    	p1.getInventory().setHelmet(null);



		}

	}
don't care about "}" (it's juste cut/paste the code)