pragma solidity ^0.4.16; 
interface tokenRecipient { function receiveApproval(address _from, uint256 _value, address _token, bytes _extraData) public; } 
contract TokenERC20 { 
    // Public variables of the token
    string public name; 
    string public symbol;
    uint8 public decimals = 18; // 18 decimals is the strongly suggested default, avoid changing it 
    uint256 public totalSupply; // This creates an array with all balances 
    mapping (address => uint256) public balanceOf; 
    mapping (address => mapping (address => uint256)) public allowance; 
    // This generates a public event on the blockchain that will notify clients 
    event Transfer(address indexed from, address indexed to, uint256 value);
    // This notifies clients about the amount burnt
    event Burn(address indexed from, uint256 value); 
    /** * Constrctor function * * Initializes contract with initial supply tokens to the creator of the contract */ 
    function TokenERC20( uint256 initialSupply, string tokenName, string tokenSymbol ) public
    { totalSupply = initialSupply * 10 ** uint256(decimals); 
    // Update total supply with the decimal amount
    balanceOf[msg.sender] = totalSupply; 
    // Give the creator all initial  tokens
    name = tokenName; 
    // Set the name for display     purposes 
    symbol = tokenSymbol; // Set the  symbol for display purposes 
    } 
    
    /** * Internal transfer, only can be called by this contract */ 
    function _transfer(address _from, address _to, uint _value) internal {
        // Prevent transfer to 0x0 address.         Use burn() instead 
        require(_to != 0x0);
        // Check if the sender has enough 
        require(balanceOf[_from] >= _value); 
        // Check for overflows
        require(balanceOf[_to] + _value > balanceOf[_to]);
        // Save this for an assertion in the future
        uint previousBalances = balanceOf[_from] + balanceOf[_to]; 
        // Subtract from the sender 
        balanceOf[_from] -= _value; 
        // Add the same to the recipient 
        balanceOf[_to] += _value; Transfer(_from, _to, _value); 
        // Asserts are used to use static analysis to find bugs in your code. They should never fail
        assert(balanceOf[_from] + balanceOf[_to] == previousBalances); }
        /** * Transfer tokens * * Send `_value` tokens to `_to` from your account * * @param _to The address of the recipient * @param _value the amount to send */ 
        function transfer(address _to, uint256 _value) public { _transfer(msg.sender, _to, _value); }
        /** * Transfer tokens from other address * * Send `_value` tokens to `_to` on behalf of `_from` * * @param _from The address of the sender * @param _to The address of the recipient * @param _value the amount to send */
        function transferFrom(address _from, address _to, uint256 _value) public returns (bool success) { require(_value <= allowance[_from][msg.sender]);
        // Check allowance 
        allowance[_from][msg.sender] -= _value; 
        _transfer(_from, _to, _value); return true; }
        /** * Set allowance for other address * * Allows `_spender` to spend no more than `_value` tokens on your behalf * * @param _spender The address authorized to spend * @param _value the max amount they can spend */ 
        function approve(address _spender, uint256 _value) public returns (bool success) { allowance[msg.sender][_spender] = _value; return true; }
        /** * Set allowance for other address and notify * * Allows `_spender` to spend no more than `_value` tokens on your behalf, and then ping the contract about it * * @param _spender The address authorized to spend * @param _value the max amount they can spend * @param _extraData some extra information to send to the approved contract */ 
        function approveAndCall(address _spender, uint256 _value, bytes _extraData) public returns (bool success) { tokenRecipient spender = tokenRecipient(_spender); if (approve(_spender, _value)) { spender.receiveApproval(msg.sender, _value, this, _extraData); return true; } } 
        /** * Destroy tokens * * Remove `_value` tokens from the system irreversibly * * @param _value the amount of money to burn */ 
        function burn(uint256 _value) public returns (bool success) { require(balanceOf[msg.sender] >= _value); 
        // Check if the sender has enough
        balanceOf[msg.sender] -= _value; 
        // Subtract from the sender
        totalSupply -= _value; 
        // Updates totalSupply 
        Burn(msg.sender, _value); return true; }
        /** * Destroy tokens from other account * * Remove `_value` tokens from the system irreversibly on behalf of `_from`. * * @param _from the address of the sender * @param _value the amount of money to burn */ 
        function burnFrom(address _from, uint256 _value) public returns (bool success) { require(balanceOf[_from] >= _value);
        // Check if the targeted balance is enough
        require(_value <= allowance[_from][msg.sender]); 
        // Check allowance 
        balanceOf[_from] -= _value;
        // Subtract from the targeted balance 
        allowance[_from][msg.sender] -= _value; 
        // Subtract from the sender's allowance 
        totalSupply -= _value;
        // Update totalSupply
        Burn(_from, _value); return true; } }