select 태그의 선택된 value 가져오기

<div class="selectChoice">
    <select name="status" id="status" onchange="fn_searchExt()">
        <option value="">전체</option>
        <option value="SUCCESS">Success</option>
        <option value="FAILURE" selected>Failure</option>
    </select>
</div>

<script type="text/javascript">
    var batchstatus = document.getElementById("status").options[document.getElementById("status").selectedIndex].value;
</script>