mapping (address => uint256) public balanceOf;
mapping (address => mapping (address => uint256)) public allowance;

event Transfer(address indexed from, address indexed to, uint256 value);

event Burn(address indexed from, uint256 value);

function NobarToken(
    uint256 initialSupply,
    string tokenName,
    string tokenSymbol
) public {
    totalSupply = initialSupply * 10 ** uint256(decimals);  
    balanceOf[msg.sender] = totalSupply;                
    name = tokenName;                                   
    symbol = tokenSymbol;                               
}


function _transfer(address _from, address _to, uint _value) internal {
    require(_to != 0x0);
    require(balanceOf[_from] >= _value);
    require(balanceOf[_to] + _value > balanceOf[_to]);
    uint previousBalances = balanceOf[_from] + balanceOf[_to];
    balanceOf[_from] -= _value;
    balanceOf[_to] += _value;
    Transfer(_from, _to, _value);
    assert(balanceOf[_from] + balanceOf[_to] == previousBalances);
}


function transfer(address _to, uint256 _value) public {
    _transfer(msg.sender, _to, _value);
}


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;
}

function approve(address _spender, uint256 _value) public
    returns (bool success) {
    allowance[msg.sender][_spender] = _value;
    return true;
}

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;
    }
}


function burn(uint256 _value) public returns (bool success) {
    require(balanceOf[msg.sender] >= _value);   
    balanceOf[msg.sender] -= _value;            
    totalSupply -= _value;                  
    Burn(msg.sender, _value);
    return true;
}


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;
}