solidty basic coin

pragma  solidity ^0.4.11;

// import './IERC20.sol';

// contract FuncToken is IERC20 {
contract FuncToken {
    
    uint public constant _totalSupply = 1000000;
    
    string public constant symbol = "FUNC";
    string public constant name = "FUNC TOKEN";
    uint8 public constant decimals = 3;
    
    mapping(address => uint256) balances;
    mapping(address => mapping(address => uint256)) allowed;
    
    function FuncToken() {
        balances[msg.sender] = _totalSupply;
    }
    
    function totalSupply() constant returns (uint256 totalSupply) {
        return _totalSupply;
    }
    
    function balanceOf(address _owner) constant returns (uint256 balance) {
        return balances[_owner];
    }
    
    function transfer(address _to, uint256 _value) constant returns (bool success) {
        require(
            balances[msg.sender] >= _value 
            && _value > 0
        );
        balances[msg.sender] -= _value;
        balances[_to] += _value;
        Transfer(msg.sender, _to, _value);
        return true;
    }
    
    function transferFrom(address _from, address _to, uint256 _value) constant returns (bool success) {
        require(
            allowed[_from][msg.sender] >= _value && _value > 0
            && balances[_from] >= _value
            && _value > 0
        );
        balances[_from] -= _value;
        balances[_to] += _value;
        allowed[_from][msg.sender] -= _value;
        Transfer(_from, _to, _value);
        return true;
    }
    
    function approve(address _spender, uint256 _value) constant returns (bool success) {
        allowed[msg.sender][_spender] = _value;
        Approval(msg.sender, _spender, _value);
        return true;
    }
    
    function allowance(address _owner, address _spender) constant returns (uint256 remaining) {
        return allowed[_owner][_spender];
    }
    
    event Transfer(address indexed _from2, address indexed _to, uint256 _value);
    event Approval(address indexed _owner, address indexed _spender, uint256 _value);
}