我想要的是,只有從下拉菜單中選擇某個選項才能訪問該文本框,並且我有如下的html表單:在多種情況下在下拉菜單中選擇一個選項啓用文本框
<tr>
<td>a. Did any of your staff participate in training or orientation sessions related to any aspect of social performance management, during the reporting year?
<td >
<select name="mfi_4_a_i">
<option>Please choose one.</option>
<option>Yes</option>
<option>No</option>
<option>No, but planning in future</option>
</select>
<p>if not,and not planning please explain why not?</p>
<input type="text" name="mfi_4_a_ii" class="init" disabled="disabled"/>
</tr>
現在,當在未來選擇否,但計劃被選中,那麼該文本必須是enabled.This下拉菜單的類型以這種形式已經被多次使用,所以我必須啓用另一個類似的情況下,文本框所以如何寫一個單一的函數來做到這一點。幫我解決問題。