javascript在ie8类型不匹配上不起作用

Question

JavaScript not working on IE8 -getting type mismatch on this particular line:

from_s.add(temp, from_s.options[0]);

I have run this search/display code on Firefox and higher version of ie's and it worked perfectly fine. I just don't get it, =(( i really really need this one to work, I hope someone out there could help me =(

Here is my code that searches for a keyword and puts it on top of the list:

JavaScript:

<script type="text/javascript">
  function searchstudent(){
    var searchvalue= document.getElementById('search').value;
    var from_s = document.getElementById('students-out');
    for (var i=0;i<from_s.options.length-1;i++){
      var st = from_s.options[i].text;
      if(st.search(searchvalue)>-1){
        var temp = from_s.options[i];
        from_s.add(temp, from_s.options[0]);
      }
   }
 }

and the form:

<form id="search2">
  <input type="text" id="search" onkeyup="searchstudent()" placeholder="Enter Keyword here.. ." /><br/><br/><br/>
  <select name="users-out" id="students-out" multiple="multiple" size="10" onchange="location = this.options[this.selectedIndex].value;">
    <option value="n.html" title="ppp">ppp</option>
    <option value="n.html" title="ppp">yyy</option>
    <option value="g.html" title="qwe">qwe</option>
    <option value="32" title="bond desk">bond desk</option>
    <option value="32" title="qqq">qqq</option>
    <option value="26" title="     ">     </option>
  </select>
</form>

Answer 1

It looks like add() does not exist on HTMLSelectElement in IE8.

Instead you could probably use the much more consistent and standardized insertBefore() DOM Node method.

from_s.insertBefore(temp, from_s.options[0]);

Or appendChild() if you want it at the end.

See also: JavaScript Error in add method using IE8