tokenReward.transferFrom(address(this),address(this),100);

interface ERC20Token {
    function transferFrom(address from, address to, uint value) public;
    function transfer(address _to, uint256 _value) public returns (bool);
}

contract AHVote {

     ERC20Token public tokenReward;    // 要卖的token
     address public owner;


     function AHVote(address addressOfTokenUsedAsReward) public{
         tokenReward = ERC20Token(addressOfTokenUsedAsReward);
         owner = msg.sender;
     }

      function vote()  public {
          tokenReward.transferFrom(msg.sender,address(this),100);
      }

    /* modifier是修改标志 */
    modifier onlyOwner {
        require(msg.sender == owner);
        _;
    }


}

Invalid JSON RPC response: {"id":2633,"jsonrpc":"2.0","error":{"code":-32603}}