[hhh]

<select id="test">
  <option>Гек</option>
  <option>Том</option>
  <option>Сид</option>
  <option>Джим</option>
</select>
<select>
  <option>Гек</option>
  <option>Том</option>
  <option>Сид</option>
  <option>Джим</option>
</select>
<script>

var selectColletion = document.querySelectorAll('select'),
    firstSelect = selectColletion[0],
    lastSelect = selectColletion[1];

    firstSelect.onchange = function() {
      if (this.selectedIndex >= lastSelect.selectedIndex) {
        lastSelect.value = this.value;

        for (var i = 0; i < lastSelect.selectedIndex; i++) {
          lastSelect.options[i].style.display = "none";
        }
      } else {
        lastSelect.value = this.value;
        for (var i = 0; i < lastSelect.length; i++) {
          if (i < lastSelect.selectedIndex) continue;
          lastSelect.options[i].style.display = "block";
        }

      }

    };

</script>