Safe Send

    contract Safe_Send {

        bool reentrant = false;

        event Attack();
        event LOG_Send(uint amount, address recipient, bool success);

        modifier noReentrant {
            if (reentrant) {
                Attack();
                return;
            }
            reentrant = true;
            _
            reentrant = false; 
        }

        mapping (address => uint) balances;
        uint totalSupply;
        
        function () noReentrant {
            balances[msg.sender] += msg.value;
            totalSupply += msg.value;
        }

        function payOut(uint amount, address recipient) noReentrant {
            if (balances[msg.sender] > amount) {
                uint balance = balances[msg.sender];
                balances[msg.sender] -= amount;
                uint oldSupply = totalSupply;
                totalSupply -= amount;
                if(!recipient.send(amount)) {
                    totalSupply = oldSupply;
                    balances[msg.sender] = balance;
                    LOG_Send(amount, recipient, false);
                    return;
                }
                LOG_Send(amount, recipient, true);
            }
        }
    }