    function changeHashOwnership(bytes32 hash, address newowner) external payable
    {
        require(contractactive == true);
        uint owncount = getHashOwnersCount(hash);
        require(owncount > 0);
        require(msg.sender == HashList[hash][owncount - 1].owner); 
        require(msg.value == changehashownerfee);
        HashRegistration memory thisregistration;
        thisregistration.owner = newowner;
        thisregistration.registrationtime = now;
        HashList[hash].push(thisregistration);
        emit ChangeHashOwnershipEvent(msg.sender, thisregistration.owner, hash, thisregistration.registrationtime);
    }