JSTL控制select为默认选择

<tr>
<td>起点：</td>
<td>
<select <c:if test="${not empty mileageObj.id}"> disabled="disabled"</c:if>>
<option value="">请选择</option>
<c:forEach var="start" items="${mileageVOObj }">
<option value="<c:out value='${start.startRepertoryUnifyCode}'/>" <c:if test="${start.startRepertoryUnifyCode == mileageObj.startRepertoryUnifyCode}">selected</c:if>>
<c:out value='${start.startRepertoryName}' />
</option>
</c:forEach>
</select>
<font color="red">*</font>
<input id="startRepertoryUnifyCode" name="startRepertoryUnifyCode" type="hidden" value="${mileageObj.startRepertoryUnifyCode }">
</td>
</tr>