    function transferFrom(address _from, address _to, uint256 _value) public returns (bool success){
		require(_to != 0x0);
        require(allowed [_from][msg.sender] >= 0 && balances[_from] >= _value && _value > 0);
        balances[_from] = balances[_from].sub(_value);
        balances[_to] = balances[_to].add(_value);
        allowed[_from][msg.sender] = allowed[_from][msg.sender].sub(_value);
        Transfer(_from, _to, _value);
        return true;
    }