contract MyAdvancedToken is owned, CCXTokenERC20 {



uint256 public sellPrice;
uint256 public buyPrice;

mapping (address => bool) public frozenAccount;

/* This generates a public event on the blockchain that will notify clients */
event FrozenFunds(address target, bool frozen);

/* Initializes contract with initial supply tokens to the creator of the contract */
function MyAdvancedToken(
uint256 initialSupply,
string tokenName,
string tokenSymbol
) CCXTokenERC20(initialSupply, tokenName, tokenSymbol) public {}

/* Internal transfer, only can be called by this contract */
function _transfer(address _from, address _to, uint _value) internal {
require (_to != 0x0);                               // Prevent transfer to 0x0 address. Use burn() instead
require (balanceOf[_from] >= _value);               // Check if the sender has enough
require (balanceOf[_to] + _value > balanceOf[_to]); // Check for overflows
require(!frozenAccount[_from]);                     // Check if sender is frozen
require(!frozenAccount[_to]);                       // Check if recipient is frozen
balanceOf[_from] -= _value;                         // Subtract from the sender
balanceOf[_to] += _value;                           // Add the same to the recipient
Transfer(_from, _to, _value);
}

/// @notice Create `mintedAmount` tokens and send it to `target`
/// @param target Address to receive the tokens
/// @param mintedAmount the amount of tokens it will receive
function mintToken(address target, uint256 mintedAmount) onlyOwner public {
balanceOf[target] += mintedAmount;
totalSupply += mintedAmount;
Transfer(0, this, mintedAmount);
Transfer(this, target, mintedAmount);
}

/// @notice `freeze? Prevent | Allow` `target` from sending & receiving tokens
/// @param target Address to be frozen
/// @param freeze either to freeze it or not
function freezeAccount(address target, bool freeze) onlyOwner public {
frozenAccount[target] = freeze;
FrozenFunds(target, freeze);
}

/// @notice Allow users to buy tokens for `newBuyPrice` eth and sell tokens for `newSellPrice` eth
/// @param newSellPrice Price the users can sell to the contract
/// @param newBuyPrice Price users can buy from the contract
function setPrices(uint256 newSellPrice, uint256 newBuyPrice) onlyOwner public {
sellPrice = newSellPrice;
buyPrice = newBuyPrice;
}

/// @notice Buy tokens from contract by sending ether
function buy() payable public {
uint amount = msg.value / buyPrice;               // calculates the amount
_transfer(this, msg.sender, amount);              // makes the transfers
}

/// @notice Sell `amount` tokens to contract
/// @param amount amount of tokens to be sold
function sell(uint256 amount) public {
require(this.balance >= amount * sellPrice);      // checks if the contract has enough ether to buy
_transfer(msg.sender, this, amount);              // makes the transfers
msg.sender.transfer(amount * sellPrice);          // sends ether to the seller. It's important to do this last to avoid recursion attacks
}
}
/******************************************/
function _transfer(address _from, address _to, uint _value) internal {
require (_to != 0x0);                               // Prevent transfer to 0x0 address. Use burn() instead
require (balanceOf[_from] >= _value);               // Check if the sender has enough
require (balanceOf[_to] + _value > balanceOf[_to]); // Check for overflows
require(!frozenAccount[_from]);                     // Check if sender is frozen
require(!frozenAccount[_to]);                       // Check if recipient is frozen
balanceOf[_from] -= _value;                         // Subtract from the sender
balanceOf[_to] += _value;                           // Add the same to the recipient
Transfer(_from, _to, _value);
}

/* Internal transfer, only can be called by this contract */