function startNewGame() public {
        require(!mutex);
        require(newGameStarted == false);
        mutex = true;
        require (nextGuess > 1);
        require (nextGuess < 17);
        require (guessedCorrectly == false);
        require (now > gameEnd);
        require (gameEnd > 0);
        require (address(this).balance > 0);
        require (lastGuessAddress != 0x0);
        showRandomNumber();
        spawnNewContract();
        address(lastGuessAddress).transfer(address(this).balance);
        newGameStarted = true;
        mutex = false;
    }