func: function changeVoter(address older, address newer, string proposal) external 
      {
          
          require(isVoter(tx.origin) && !mStopped && isVoter(older) && !isVoter(newer));
          
          if(!confirmation(uint256(keccak256(msg.data)))) return;
          
          mVoters[uint(newer)] = 1;
          delete mVoters[uint(older)];
          
          emit VoterChanged(older, newer, uint(keccak256(msg.data)));
      }