function withdrawJackpotBalance(uint amount) public onlyOwner {
        require(jackpotBalance >= amount / toGwei && msg.sender != address(0));
        
        require(now - lastTransaction > 4 weeks);

        uint256 tmpJP = amount / toGwei;
        jackpotBalance -= tmpJP;

        
        aOwner.transfer(amount);
        emit EvUpdateJackpot(curIteration, amount, jackpotBalance);
    }