我正在處理具有多個(gè)下拉選項(xiàng)的表單。我在下面的表格中將所有內(nèi)容簡(jiǎn)化為三個(gè)問(wèn)題，以說(shuō)明我的問(wèn)題。我已經(jīng)嘗試過(guò)此代碼（以及一些變體）：function update_variables(el, standard_val, var_list) {  standard_val.value = var_list[el.getElementsByTagName('option')[el.selectedIndex].value];}var select2 = document.getElementById('think_question'),  hidden_answer = document.getElementsByName('thought_goes_here')[0];var why_options = {  'yes': '',  'no': 'Well, you tried.'};select2.addEventListener('change', function() {  update_variables(select2, hidden_answer, why_options);});var sel_group_control = document.getElementById('follower_question');var sel_free_will = document.getElementById('think_question');sel_group_control.addEventListener('change', answer_bypass);function answer_bypass() {  var user_choice = sel_group_control.value;  if (user_choice === 'no') {    sel_free_will.selectedIndex = 2;    sel_free_will.style.backgroundColor = "#D3D3D3";    sel_free_will.disabled = true;  }}<h2>Life Decisions</h2><form>  Be exactly like everone else?  <select id='follower_question'>    <option disabled selected value> -- select an option -- </option>    <option>yes</option>    <option>no</option>  </select>  <br> Think for yourself?  <select id='think_question'>    <option disabled selected value> -- select an option -- </option>    <option>yes</option>    <option>no</option>  </select>  <br> Original thought:<input name="thought_goes_here" size="50" value="" id="your_thoughts"></form>如果將問(wèn)題2設(shè)置為“否”，則已知問(wèn)題3的答案，并在其中填寫回答。如果問(wèn)題1為“否”，則問(wèn)題2應(yīng)設(shè)置為“否”且為只讀。我希望在回答問(wèn)題1時(shí)選擇“否”時(shí)，問(wèn)題3也將自動(dòng)更新，但該功能似乎被忽略了。