select 控件js

      <form action="user.do?method=modifyUserAnswer" name="pwdProtect" method="post"  onsubmit="return setAnswer()" >
       <strong
        style="color: #FF0000;font-size: 14px;margin-bottom: 18px;">设置密码保护：</strong>
       <div class="g-collection-item">
        <label class="g-collection-label">
         <span class="txt-impt">*</span>&nbsp;密码保护问题&nbsp;
        </label>
        <div id="questWrap" class="ipt-wraper ">
         <select onchange="changeQuestion(this)" style="width: 310px"
          class="g-select" id="question" name="question">
          <option value="0">
           -请选择-
          </option>
          <option value="您的出生地是？">
           您的出生地是？
          </option>
          <option value="您父亲的出生地是？">
           您父亲的出生地是？
          </option>
          <option value="您母亲的出生地是？">
           您母亲的出生地是？
          </option>
          <option value="您身份证号码的最后6位是？">
           您身份证号码的最后6位是？
          </option>
          <option value="您手机号码的最后6位是？">
           您手机号码的最后6位是？
          </option>
          <option value="您父母家的固定电话号码最后6位是？">
           您父母家的固定电话号码最后6位是？
          </option>
          <option value="您母亲的姓名是？">
           您母亲的姓名是？
          </option>
          <option value="您父亲的姓名是？">
           您父亲的姓名是？
          </option>
          <option value="您配偶的姓名是？">
           您配偶的姓名是？
          </option>
          <option value="selfquestion">
           您的自定义问题
          </option>
         </select>
         <p class="notice isquestWrap">
          <b class="ico ico-succ"></b>
          <span class="txt-succ"></span>
         </p>
        </div>
        <div class="txt-info" id="passwquNot">
         密码遗忘或被盗时，可通过回答密码保护问题取回密码
        </div>
       </div>

       <div style="display: none;" id="selfQuestion"
        class="g-collection-item">
        <label class="g-collection-label">
         <span class="txt-impt">*</span>&nbsp;自定义问题&nbsp;
        </label>
        <div id="selfqWrap" class="ipt-wraper">
         <input type="text" class="g-ipt" id="questionNew"
          name="questionNew">
        </div>
        <div class="txt-info" id="passwquselfNot">
         6~30个字符，一个汉字占两个字符
        </div>
       </div>

       <div class="g-collection-item">
        <label class="g-collection-label">
         <span class="txt-impt">*</span>&nbsp;答案&nbsp;
        </label>
        <div id="answerWrap" class="ipt-wraper ">
         <input type="text" class="g-ipt" id="answer" name="answer">
         <p style="display: none" class="notice">
          <b class="ico ico-warning"></b>
          <span class="txt-err">错误提示</span>
         </p>
        </div>
        <div class="txt-info" id="passwanNot">
         4~30个字符，一个汉字占两个字符，区分大小写
        </div>
       </div>

       <div style="text-align: center;margin-top: 25px;">
        <input style="height: 60px;width: 300px;font-size: 20px"
         type="submit" value="设 置 密 保">
       </div>
      </form>
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function  changeQuestion(me)
 {
   var value = me.options[me.selectedIndex].text;
         var question = document.getElementById("selfQuestion");
         var newquestion=document.getElementById("questionNew");
         var answer=document.getElementById("answer");
   if (me.selectedIndex==10)
   {
              question.style.display = "block";
              if(newquestion=="")
              {
               alert('请输入自定义问题！');
               
              }
              if(answer=="")
              {
               alert('请输入自定义问题答案！');
              }
             
   }
   else
   {
    question.style.display = "none";
    if(answer="")
    {
     alert('请输入密保问题答案！');
    }
   }
 }
 
 function  setAnswer()
 {
 
         var question = document.getElementById("selfQuestion");
         var newquestion=document.getElementById("questionNew").value;
         var answer=document.getElementById("answer").value;
       
  if(document.getElementById("question").selectedIndex==0)
   {
    alert('请选择密保问题！');
    document.forms["pwdProtect"].elements["question"].focus()
          return false;
   }
  else if(document.getElementById("question").selectedIndex!=10)
   {
    
    if(answer== "")
    {
     alert('请输入密保问题答案！');
     document.forms["pwdProtect"].elements["answer"].focus()
           return false;
    }
   }
  else
  {
   changeQuestion(document.getElementById("question"));
   if(newquestion== ""){
   
    alert('请输入自定义问题')
    document.forms["pwdProtect"].elements["questionNew"].focus();
          return false;
   }
   if(answer=="")
   {
    alert('请输入自定义问题答案！')
    document.forms["pwdProtect"].elements["answer"].focus();
          return false;
   }
   
  }
   
   
   return true;
  
  
 }