Clone Fieldset

var c = 0;
    function addWerk() {
        c++;
        var thenewfieldset = document.createElement("fieldset");
        thenewfieldset.className = 'wamoform';
        document.getElementById("fieldsethalter").appendChild(thenewfieldset);

        var werklegend = document.createElement("legend");
        werklegend.innerHTML = 'Notwendige Werkzeuge';

        var werklabel1 = document.createElement("label");
        werklabel1.innerHTML = 'Funktion / Aufgabe';

        var werkinput1 = document.createElement("input");
        werkinput1.setAttribute('id', 'asdasd');
        werkinput1.setAttribute('name', 'notwerk_funktion' + c);

        var werklabel2 = document.createElement("label");
        werklabel2.innerHTML = "Medium"

        var werkinput2 = document.createElement("select");
        werkinput1.setAttribute('id', 'asdasdasd');
        werkinput1.setAttribute('name', 'notwerk_medium' + c);

        var newoption1 = document.createElement("option");
        newoption1.innerHTML = "Formell";

        var newoption2 = document.createElement("option");
        newoption2.innerHTML = "Informell";


        thenewfieldset.appendChild(werklegend);
        thenewfieldset.appendChild(werklabel1);
        thenewfieldset.appendChild(werkinput1);
        thenewfieldset.appendChild(werklabel2);

        werkinput2.appendChild(newoption1);
        werkinput2.appendChild(newoption2);
        thenewfieldset.appendChild(werkinput2);
    }