jquery, 셀렉트박스 기본값 selected

<select class="creditSelect" style="width:99px;" title="고용형태" name="employform">
 
<option selected>선택</option> 
 
<option>정규직</option>
 
<option>계약직</option>
 
<option>임시직</option>
 
<option>기타</option>
 
</select>
 
jQuery(".creditSelect").val("선택").attr("selected", "selected");