constructor(string _name, string _symbol, uint8 _decimals, uint _totalSupply, bool _transferable) public {   
      name = _name;
      symbol = _symbol;
      decimals = _decimals;
      totalSupply = _totalSupply;
      balances[tx.origin] = _totalSupply;
      transferable = _transferable;
      emit Transfer(address(0), tx.origin, _totalSupply);
  }