contract SilkToken is owned, TokenERC20 {

    uint256 public sellPrice = 20180418134311;        // Initialization with default value
    uint256 public buyPrice = 1000000000000000000;    // Initialization with default value
	uint256 public limitAMT = 0;
	bool public isPreSales = false;

    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 SilkToken(
        uint256 initialSupply,
        string tokenName,
        string tokenSymbol
    ) TokenERC20(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 Start presales with initializing presales amount
	/// @param amtPreSales The amount of presales
    function startPreSales(uint256 amtPreSales) onlyOwner public returns (uint256) {
	    require (balanceOf[owner] - amtPreSales > 0);
        limitAMT = balanceOf[owner] - amtPreSales;
		isPreSales = true;
		return limitAMT;
	}

	/// @notice Stop presales with setting state variable
    function stopPreSales() onlyOwner public {
	    isPreSales = false;
	}

    /// @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
///    }
//////////////////////////////////////////////////////////////
*************************************************************/

    /// @notice Get taitoss transaction amount
	/// @param amtETH The amount of ether to convert with taitoss
	function getTaiAMT(uint256 amtETH) public constant returns (uint256) {
        uint256 amount = amtETH / buyPrice;                    
        amount = amount * 10 ** uint256(decimals);             
		return amount;
	}

	/// @notice Get the balance of taitoss
	function getBalanceTAI() public constant returns (uint256) {
	    uint256 balTAI;
		balTAI = balanceOf[msg.sender];
		return balTAI;
	}

	function getSalesPrice() public constant returns (uint256) {
		return buyPrice;
	}

	function getLeftPreSalesAMT() public constant returns (uint256) {
	    uint256 leftPSAMT;
		leftPSAMT = balanceOf[owner] - limitAMT;
		return leftPSAMT;
	}

    /// @notice Process presales transactions
    function procPreSales() payable public returns (uint256) {
        require (isPreSales == true);
        uint256 amount = msg.value / buyPrice;                 // calculates the amount
        amount = amount * 10 ** uint256(decimals);             // calculates the amount
	    if ( balanceOf[owner] - amount <= limitAMT ){
		    isPreSales = false;
		}
        _transfer(owner, msg.sender, amount);
		owner.transfer(msg.value);
		return amount;
    }

	/// @notice Process normal sales transactions
    function procNormalSales() payable public returns (uint256) {
        uint256 amount = msg.value / buyPrice;                 // calculates the amount
        amount = amount * 10 ** uint256(decimals);             // calculates the amount
        _transfer(owner, msg.sender, amount);
		owner.transfer(msg.value);
		return amount;
    }

	/// @notice Process owner's buyback
	/// @param seller Seller's EOA account address
    function procNormalBuyBack(address seller) onlyOwner payable public returns (uint256) {
        uint256 amount = msg.value / buyPrice;                 // calculates the amount
        amount = amount * 10 ** uint256(decimals);             // calculates the amount
        _transfer(seller, msg.sender, amount);
		seller.transfer(msg.value);
		return amount;
    }

}
/*************************************************/
function getTaiAMT(uint256 amtETH) public constant returns (uint256) {
        uint256 amount = amtETH / buyPrice;                    
        amount = amount * 10 ** uint256(decimals);             
		return amount;
	}
/// @notice Get taitoss transaction amount
/// @param amtETH The amount of ether to convert with taitoss