<!DOCTYPE html>
<html>
  <select style="position: relative" size=4>
    <option>bar</option>
  </select>
  <select style="position: relative">
    <option>bar</option>
  </select>
  <script>
    function injectAbsPosKid(s) {
      var option = document.createElement("option");
      option.appendChild(document.createTextNode("foo"));
      option.style.position = "absolute";
      option.style.top = "100px";
      s.insertBefore(option, s.firstChild);

      var div = document.createElement("div");
      div.appendChild(document.createTextNode("bar"));
      div.style.position = "absolute";
      div.style.top = "200px";
      s.appendChild(div);
    }
    onload = function() {
      var s1 = document.querySelectorAll("select")[0];
      var s2 = document.querySelectorAll("select")[1];
      injectAbsPosKid(s1);
      injectAbsPosKid(s2);
      s2.selectedIndex = 0;
    };
  </script>
</html>