Untitled

<!DOCTYPE html>
<html>
<body>

Puec

<input id="Dwa"  type="radio" name="dwa" onclick="kobjeta()"/>Męszczyzna

<input id="Trzy" type="radio" name="dwa" onclick="kobjeta()"/> Kopieta


<div id="Cztery" style='display: none'>Nazwisko Panieńskie
    <input type='text' id='yes' name='yes'/>
    </div>

<script>

    function kobjeta() {
        if (document.getElementById('Dwa').checked) {
            document.getElementById('Cztery').style.display = 'none';
        }
        else {
            document.getElementById('Cztery').style.display = 'block';
        }
    }

</script>

</body>
</html>