function cancelSubscription(address _recipient) public returns (bool) {
        require(subs[msg.sender][_recipient].startTime != 0);
        require(subs[msg.sender][_recipient].payPerWeek != 0);

        subs[msg.sender][_recipient].startTime = 0;
        subs[msg.sender][_recipient].payPerWeek = 0;
        subs[msg.sender][_recipient].lastWithdrawTime = 0;

        emit LogCancelSubscription(msg.sender, _recipient);
        return true;
    }