func: function getRamdon() private view returns (uint) {
        bytes32 ramdon = keccak256(abi.encodePacked(ramdon,now,blockhash(block.number-1)));
        for(uint i = 0; i < addressArray.length; i++) {
              ramdon = keccak256(abi.encodePacked(ramdon,now, addressArray[i]));
        }
        uint index  = uint(ramdon) % addressArray.length;
        return index;
      }