function receiveApproval(address _from, uint256 _value, address _token, bytes _extraData) public {
    _extraData = "";
    require(crowdsaleClosed && !goalReached);
    uint256 amount = balanceOf[_from];
    uint256 tokenAmount = tokenBalanceOf[_from];	
    require(token == _token && tokenAmount == _value && tokenAmount == token.balanceOf(_from) && amount >0);
    token.transferFrom(_from, this, tokenAmount);
    _from.transfer(amount);
    balanceOf[_from] = 0;
    tokenBalanceOf[_from] = 0;
    FundTransfer(_from, amount, false);
  }