Html中 標簽的隱藏與顯示

TR標簽的隱藏與顯示：block(顯示)和none(隱藏) 

 <tr  style="display:none"> 

<tr id="sample"
            style="display: <s:if test="sample == 1">block</s:if><s:else>none</s:else>">
            <td>
                sample
            </td>
</tr>
<script type="text/javascript">
function changeTR(selectedValue)
{
    var tr1 = document.getElementById("sample");

    if (selectedValue == 0)
    {
        tr1.style.display = 'block';
    }
    else
    {
        tr1.style.display = 'none';
    }
}
</script>