コントロールの動的配置について

<script type="text/javascript">
<!--
    function SelectLanguage(selItem) {
        SetLabel(selItem);
        var set = document.getElementById("set1");
        var it1 = document.getElementById("item1");
        var it2 = document.getElementById("item2");
        var it3 = document.getElementById("item3");
        set.removeChild(it1);
        set.removeChild(it2);
        set.removeChild(it3);
        if (selItem.value == "ja") {
            set.appendChild(it1);
            set.appendChild(it2);
            set.appendChild(it3);
        } else if (selItem.value == "en") {
            set.appendChild(it1);
            set.appendChild(it3);
            set.appendChild(it2);
        }
    }

    function SetLabel(selItem) {
        var it1 = document.getElementById("input1label");
        var it2 = document.getElementById("input2label");
        var it3 = document.getElementById("input3label");
        if (selItem.value == "ja") {
            it1.innerText = "郵便番号";
            it2.innerText = "住所１";
            it3.innerText = "住所２";
        } else if (selItem.value == "en") {
            it1.innerText = "Zip code";
            it2.innerText = "City, State";
            it3.innerText = "Street";
        }
    }
// -->
</script>

<fieldset style="background-color:#EEEEEE;">
    <label for="sel1">日本語</label><input name="language" type="radio" value="ja" onClick="SelectLanguage(this);" />
    <label for="sel2">English</label><input name="language" type="radio" value="en" onClick="SelectLanguage(this);" />
</fieldset>
<form>
<fieldset id="set1" style="background-color:#EEEEEE;">
    <div id="item1"><label for="input1" id="input1label"></label><input id="input1" type="text" /></div>
    <div id="item2"><label for="input2" id="input2label"></label><input id="input2" type="text" /></div>
    <div id="item3"><label for="input3" id="input3label"></label><input id="input3" type="text" /></div>
</fieldset>
</form>