func: function createToken(
          string  name,
          string  symbol,
          uint8   decimals,
          uint    totalSupply
          )
          public
          returns (address addr)
      {
          require(tokenRegistry != 0x0);
          require(symbol.checkStringLength(3, 10));
          bytes10 symbolBytes = symbol.stringToBytes10();
          require(tokens[symbolBytes] == 0x0);
          ERC20Token token = new ERC20Token(
              name,
              symbol,
              decimals,
              totalSupply,
              tx.origin
          );
          addr = address(token);
          TokenRegistry(tokenRegistry).registerMintedToken(addr, symbol);
          tokens[symbolBytes] = addr;
          emit TokenCreated(
              addr,
              name,
              symbol,
              decimals,
              totalSupply,
              tx.origin
          );
      }