[Crazy]

<script>
function update_s2() {
  var selected = document.main.s1[document.main.s1.selectedIndex].value;
  document.main.s2.clear;
  var i;
  for(i=0; i<10; i++) {
    document.main.s2.options[i] = new Option(selected+" "+i,i,false,false);
  }
}
</script>
<form name="main">
  <select name="s1" onChange="update_s2()">
    <option value="a">foo</option>
    <option value="b">bar</option>
    <option value="c">buzz</option>
  </select>
  <select name="s2">
  </select>
</form>