我的选择(下拉)框有问题...
问题是我有一组下拉菜单,每个下拉菜单都有一组下拉菜单..
在更改下拉列表时,所有子下拉列表都由更改的值选择
请帮我
以下代码具有下拉框
当父下拉列表更改时,所有子下拉列表将由该更改的值选择
<table>
<tr>
<th>Parent DropDown</th>
<th colspan="3">Child Dropdowns</th>
</tr>
<tr>
<td>
<select name="class_1" id="class_1">
<option value="First">First</option>
<option value="Second">Second</option>
</select>
</td>
<td>
<select name="subClass_1" class="select_1">
<option value="First">First</option>
<option value="Second">Second</option>
</select>
</td>
<td>
<select name="subClass_2" class="select_1">
<option value="First">First</option>
<option value="Second">Second</option>
</select>
</td>
<td>
<select name="subClass_3" class="select_1">
<option value="First">First</option>
<option value="Second">Second</option>
</select>
</td>
</tr>
<tr>
<td>
<select name="class_2" id="class_2">
<option value="First">First</option>
<option value="Second">Second</option>
</select>
</td>
<td>
<select name="subClass_1" class="select_2">
<option value="First">First</option>
<option value="Second">Second</option>
</select>
</td>
<td>
<select name="subClass_2" class="select_2">
<option value="First">First</option>
<option value="Second">Second</option>
</select>
</td>
<td>
<select name="subClass_3" class="select_2">
<option value="First">First</option>
<option value="Second">Second</option>
</select>
</td>
</tr>
<tr>
<td>
<select name="class_3" id="class_3">
<option value="First">First</option>
<option value="Second">Second</option>
</select>
</td>
<td>
<select name="subClass_1" class="select_3">
<option value="First">First</option>
<option value="Second">Second</option>
</select>
</td>
<td>
<select name="subClass_2" class="select_3">
<option value="First">First</option>
<option value="Second">Second</option>
</select>
</td>
<td>
<select name="subClass_3" class="select_3">
<option value="First">First</option>
<option value="Second">Second</option>
</select>
</td>
</tr>
</table>