function receiveApproval(address _from,uint256 _value,address _token,bytes _extraData) external ;
}
contract GrowToken{
    
    address public owner;
    string public name;
    string public symbol;
    uint8 public decimals;
    uint256 public totalSupply;
    uint256 public sellPrice; 
    uint256 public buyPrice;
    bool public sellOpen;
    bool public buyOpen;
    
    
    mapping(address => uint256) public balanceOf;
    
    mapping(address => mapping(address => uint256)) public allowance;
    
    mapping(address=>bool) public frozenAccount;
    
    
    event Transfer(address indexed from,address indexed to , uint256 value);
    
    event Approval(address indexed owner,address indexed spender,uint256 value);
    
    event FrozenFunds(address target,bool freeze);
    
    event SellToken(address seller,uint256 sellPrice, uint256 amount,uint256 getEth);
    
    event BuyToken(address buyer,uint256 buyPrice,uint256 amount,uint256 spendEth);
    
    modifier onlyOwner {
        require(msg.sender == owner);
        _;
    }