private static final boolean exchange(L2PcInstance player, int objectId)
	{
		L2ItemInstance item = player.getInventory().getItemByObjectId(objectId);
		if (item == null)
			return false;
		
		// check enchant level
		if (item.getEnchantLevel() < 10)
			return false;
		
		// check grade
		if (item.getItem().getCrystalType() != L2Item.CRYSTAL_A)
			return false;
		
		// find the replace item
		int id = item.getItemId();
		int exchange = 0;
		for (int[] itemData : ITEMS)
		{
			if (itemData[0] != id)
				continue;
			
			exchange = itemData[1];
			break;
		}
		
		// found replace item?
		if (exchange == 0)
			return false;
		
		// remove origin and add replace item
		if (player.destroyItem("ExchageRemove", item, player, true))
		{
			player.addItem("ExchangeAdd", exchange, 1, player, true);
			return true;
		}
		
		return false;
	}