function sendTokens(address _user) public onlyOwner returns (bool) {
        require(_user != address(0));
        require(_user != address(this));
        require(purchaseLog[_user].kycApproved);
        require(purchaseLog[_user].vztValue > 0);
        require(!purchaseLog[_user].tokensDistributed);
        require(!refundLog[_user]);
        purchaseLog[_user].tokensDistributed = true;
        purchaseLog[_user].lastDistributionTime = now;
        totalDistributed++;
        token.sendToken(_user, purchaseLog[_user].vztValue);
        TokenDistributed(_user, purchaseLog[_user].vztValue);
        return true;
    }